context
stringlengths 545
71.9k
| questionsrc
stringlengths 16
10.2k
| question
stringlengths 11
563
|
|---|---|---|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right .
|
wo n't the force of friction also play a part when the second guy ( in the last scenario ) is pushing ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
what is the force called when you are pushing against something , and the other force is pushing back on you ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity .
|
does n't friction act in the last scenario ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards .
|
can there be two normal force on one object if there are multiple objects touching the object ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth .
|
so is a balanced force were everything cancels out and unbalanced were everything does not cancel out ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios .
|
friction does not care about direction right ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out .
|
if the character exerts a force on the rock , should n't there be a force exerted by the rock on the character according to newton 's third law ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
how is force of man=3n while frictional force=2n ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards .
|
wo n't both be equal ( newton 's 3rd law of motion ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing .
|
how would calculate the amount of friction if you were given the mass of the object ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios .
|
and why would friction not be effected if you applied a stronger force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
is force of gravity ( downward ) always equal to normal force ( upward ) ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right .
|
on the last example , would n't there be a force of friction to the right of 2n caused by the second guy on the right pushing towards the left ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction .
|
why in the third and fifth scenarios is there less force pushing back at the guy ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction .
|
why are anticlockwise forces considered to be positive and clockwise forces to be negative.. ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
why is it that when the `` character '' applies 2 n of force on the rock in the horizontal direction , the force of friction cancels it out by an equal and opposite force but when the `` character '' applies 3 n the force of friction still applies 2 n ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green .
|
when the rock is on the ground , why does the ground apply an equal force on it upwards ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground .
|
how do you find the distance a block will slide when you are only given the incline of the plane ( 10 degrees ) and the constant velocity ( 6 m/s ) ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
with an unbalanced force with a net force of newtons on the right , how do you calculate the acceleration ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left .
|
in the pictures with the guy pushing the rock horizontally , is there normal force in the horizontal direction ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green .
|
would that normal force affect the horizontal net force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards .
|
would n't the force of the characters have to be greater than 5 in both scenarios to even move the rock ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
say if i were the system of interest , would there be a net force on me which causes me to feel the sensation ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction .
|
or does it continuously take 3 newtons of force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward .
|
how is the weight of an astronaut in the outer space in relation with his actual weight ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity .
|
is weight of the object acting on the ground as well ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards .
|
as in if we make a free body diagram of the ground and the objects weight acting downwards on it , what is balancing this force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ?
|
in the last scenario , does n't the guy on the left also experience a force of friction of 2n ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
if an object is floating on water , then what is the net force applied to it ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards .
|
can you describe what is normal force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards .
|
so what about winds in the area for the 4th example , would n't winds have a role no matter how windy it is ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction .
|
5 why was friction counteracting the purple guy 's pushing , but not the orange guy 's pushing ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder .
|
eg , why was the 2n force added to the orange guy 's 1n push , rather than the purple guy 's 4n push ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
what would happen if the force of friction was larger than the force that guy was applying ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out .
|
i think the rock would n't start accelerating to the left , so does that make friction a normal force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards .
|
so for the inclined surface i can not use normal force as fg-mg -fgy ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards .
|
the rock is pushing down on the air with 5n so should n't the air push up on the rock with 5n ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
why is air resistance different than normal force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced .
|
but is the drag coefficient going to be constant for a given object at any speed ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground .
|
what are the factors that the drag coefficient relies on ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity .
|
whether there is also a frictional force to the right in the last scenario ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards .
|
does this mean that though the rock is n't moving anywhere , there is acceleration ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground .
|
mew *r* ) is equal to static fricton ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction .
|
will the gravity and normal forces always balance each other inspite of object 's motion ( constant & unconstant velocity ) ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios .
|
how can the force of friction change ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards .
|
in reference to the 5n rock falling with 1n air resistance , would a 4n rock falling in a vacuum fall with the same velocity ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right .
|
why does n't the smaller person experience any friction against him ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
in the 3d and 5th scenario , would the rock move at the same speed or accelerate at the same rate since both scenarios have a net force of 1 n to the right ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards .
|
can friction be considered a normal force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction .
|
why isnt there air resistance in scenario 3 and 5 ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right .
|
for the last diagram drawn , would n't the second person also encounter friction ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
is a net force the same as a resultant force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity .
|
in the 5th diagram , may i ask what is the resultant force acting on the first man ( who gives 4n force ) ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
or 4n plus 3n , adding up the reaction force by the rock on the man and the force acted by the second man who gives 3n , to be 7n in total ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
how does net force relate to equilibrium ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
does n't friction always increase to equal the force against it ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right .
|
does n't that mean that there should be 3n of friction in picture 3 ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards .
|
why is the force of gravity only 5n ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios .
|
what determines the amount of friction in opposition to an applied force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
in the case of the first picture should'nt it be like , no matter how much force you use to lift the object the object would move even if the force is microscopic ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction .
|
this may sound silly , but if two forces are balanced why does a object move at a constant velocity instead of being stationary ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so if a person pushes a heavy truck should n't the truck move because the force is unbalanced ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards .
|
the person 's hand does not go in the rock because the rock pushes him back with equal force , right ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
c. how does the force of friction on thee wagon compare with the force of the child 's pull ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards .
|
what does `` 5 newtons '' mean ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up .
|
if air resistance was 5 what would happen then ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction .
|
in the 4th scenario would'nt the force of friction also help the fist person by going againdt the second person ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green .
|
do the force of friction remains same for an object on a given ground ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards .
|
gravity and up thrust or gravity and water resistance ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction .
|
the guy is pushing the rock with 2n what about the rock pushing the guy back with 2n ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right .
|
and why is n't there force of friction for the second guy pushing the rock ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
how do you measure the force of a force ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
is the `` normal force '' and `` air resistance '' the same ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
can the net force ever be negative ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out .
|
does the force of gravity and friction have to equal the same as the opposing force up until the opposing force is greater ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right .
|
like let 's say although friction at it 's peak is 2n , and the guy is pushing at a force of 1n , would friction also be 1n ?
|
you 'll hear the terms , balanced forces and unbalanced forces a lot when you 're dealing with physics and what i wan na do in this video is give you a bunch of scenarios and have you think about whether the forces in these scenarios are balanced or unbalanced . so let 's start with the scenario where we have the ground . and then sitting on the ground we have a rock . now the force of gravity is going to be pulling the rock downwards towards the center of the earth and it 's going to be pulling it , as essentially the weight of the rock , it 's going to be pulling it downwards , let 's say with a force of 5 n downwards . but then the rock is being supported by the ground , the ground is keeping it from being plummeted downward . so the ground is providing an upwards force or normal force in this situation . the ground is providing a normal force , i 'll do it in green . the ground is providing a normal force in this situation . so these forces have the same magnitudes but they 're going in opposite directions . so that is the first scenario . now let 's think about another scenario . so i 'll draw the rock again . we 'll assume it 's the same rock . the force of gravity is still downwards . 5 n downwards . and there 's still a normal force , the ground supporting the rock of 5 n upwards . 5 n upwards . and now there 's some character who 's trying to push the rock . so we have some character here and he 's trying to push the rock and he 's applying a force of 2 n to the right . but then there 's a force of friction between the rock and the ground that is going 2 ... i 'll do friction in orange 2 n to the left so that right over there is the force of friction . it 's going against that guy 's pushing . now let 's do another scenario . once again a very similar scenario . let 's draw another scenario where i have a rock now . maybe the same rock . and here i have a 5 n force downwards . force of gravity , like the rest of the scenarios . and i have the normal force . the rock is being supported by the ground 5 n upwards . and this guy over here has been able to push a little bit harder . he 's pushing a little bit harder . he really put his back into it . and now he 's pushing with a force of 3 n to the right and the force of friction is still 2 n to the left . so that right over there is the force of friction . now let 's do a couple of more scenarios . now let 's imagine that this is the ground . and i have the rock . the rock is not resting on the ground . so the only force i have acting on the rock right now is the force of gravity , acting downward . we 're assuming we 're not going to think too much about -- actually let 's think about it a little bit , let 's also put , so let 's put it ... so i have the force of gravity . that 's 5 n down . but i have some air resistance here . you can view it as the force of friction of the air , and let 's say that is 1 n up . this is the force of friction or you can call it air resistance . as if this thing bumps into all of the air particles as it is falling to the ground . the last scenario i 'll draw with the rock again as that seems to be the theme of the video . the last scenario , that 's the ground . the rock is resting on the ground . the rock is resting on the ground . so i have the force of gravity , 5 n downwards . the rock is being supported by the ground , 5 n upwards . and now this guy is pushing really hard . so now he 's applying 4 n in that direction . you have 2 n from the force of friction , i wo n't that draw just yet ; and you also have another character right over here , who is trying to keep this guy from pushing the rock . so he 's pushing in the other direction at 1 n. so you have 2 n of the force of friction . you have this guy pushing 1 n against this guy 's motion to the left , so between this guy and the force of friction , you have 3 n going left . so now i 'll let you think about which of these have an unbalanced force in them , or another way to think about it , which of these have a net force going on ? so let 's look at the first scenario , we have a 5 n force of gravity acting towards the centre of the earth . 5 n normal force of the ground supporting the rock . these have the same magnitude in the exact opposite directions so they cancel out . these forces completely balance each other out . there is zero net force going on , there are no forces the way i 've drawn it , going on in the horizontal direction . so you have zero net force , these right here are balanced . we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other . then in the horizontal direction , this guy is pushing of 2 n to the right is being completely balanced by the force of friction of 2 n to the left . because they 're balanced there is no net force and this rock is n't going to accelerate . so once again these are all balanced forces or there 's no net force going on right over here . in scenario 3 . once again , in the vertical direction . the force of gravity is being balanced by the normal force of the ground . keeping the rock from plummeting or accelerating towards the centre of the earth . and you do have two forces that are counteracting on the horizontal direction . this guy 's pushing harder with 3 n , but the force of friction is now 2 n to the left . so you do have a net force to the right . 3 n to the right , 2 n to the left . you have a net force of 1 n to the right . or you see it 's right based on how i drew the vector . so you do have a net force or in another way of thinking about it , that this is a scenario where you have unbalanced forces , in particular , in the right left direction . now let 's look at scenario 4 . we only have forces acting in this vertical direction . you have the force of gravity 5 n downwards . you have a counteracting force , the force of air resistance , i n upward . but they do n't completely balance out . there is still a net force of 4 n downwards . therefore this is an unbalanced situation . and finally in the last scenario . we 're sitting on the ground in the vertical direction , normal force counteracting the force of gravity . those are balanced . but in the horizontal direction . to the right we have more force , 4 n , than what we have going to the left . 3 n is the guy on the right plus the force of friction . so in this situation there is a net force in the rightward direction . a 1 n force to the right or 1 n net force . this is a scenario where we have unbalanced forces .
|
we would not consider this one of the scenarios we see an unbalanced force . let 's go to scenario 2 . once again , 5 n up and 5 n down , they are balancing each other .
|
and does the same go for gravity ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see .
|
why is pattern a your horizontal axis , and pattern b is your vertical axis ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
so , would the formula be n=3 ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see .
|
when sal makes the graph , does it matter on which axis that the patterns go on ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 .
|
on a graph my daughter has x is -4 and y is 4 what is the `` rule '' ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 .
|
why did n't sal write 1 at the x axis 9 in the video ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a .
|
how do you add translated captions ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 .
|
0 does n't the numbers in a add by itself too ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns .
|
from the points given in the video can we say that for any value of x , the value of y is constant ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 .
|
what does `` constant '' mean ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 .
|
what is a constant number ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b .
|
i know what an ordered pair is , but what exactly does the term `` ordered pair '' mean ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see .
|
what would happen if you put pattern a on the vertical axis ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time .
|
does patter b always vertical ?
|
below are ordered pairs that represent the first six terms of two given patterns . the first value in each pair is a term from pattern a . and the second value is a term from pattern b . in the answer box , there are different statements about the two patterns . choose all correct statements . so let 's think about what 's going on here . they said the first term is pattern a . so the first term in each of these coordinates is pattern a , or in each pair is pattern a . so pattern a goes from 1 , to 2 , to 4 , to 8 , to 16 , to 32 . so it looks like pattern a , to go from the first term to the second term , we multiplied by 2 . and then to go from the second to the third term , we also multiplied by 2 . and we just keep multiplying by 2 . and we just keep doing that . 8 times 2 is 16 . 16 times 2 is 32 . now let 's think about what 's going on with pattern b . so pattern b is the second number in each of these pairs . and it 's just always 3 . so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time . or you could say that pattern b starts at 3 , and we are multiplying by 1 every time . either of those would give you just 3 showing up over and over again . so now that we 've looked at these pairs , we show the corresponding terms for pattern a and pattern b , let 's look at the choices here and see which of these apply . in pattern a , you can get from any term to the next by multiplying by a constant number . well , that looks right . we go from the first term to the second term by multiplying by 2 . then we multiply by 2 again to get to the third term . then we keep multiplying by 2 . so that constant number that we 're multiplying by to get to the next term is 2 . so this looks right . the next pair should be 52 comma 3 . so let 's think about this . if we keep doubling for pattern a -- so this is going to be times 2 . 32 times 2 is 64 . and then if we 'd say that this is 1 times the previous term , we 're just going to get a 3 again . so it should be 64 comma 3 should be the next one . they say the next pair should be 52 comma 3 . so that 's not right . if we graph the pairs , the points will be on the same line . so let 's think about that a little bit . let 's think about that . so this is my vertical axis . this is my horizontal axis . on the horizontal axis , i will graph pattern a . and on my vertical axis , i will graph pattern b . and let 's see . pattern a goes all the way up to 32 . so i 'm going to try my best here . so let 's say that this is 32 . then half of that is going to be 16 . half of that is going to be 8 . half of that is going to be 4 . half of that is going to be 2 . and half of that is going to be 1 . so these are all the points on pattern a . but for any of them , the corresponding term on pattern b is 3 . so we have , when pattern a is 1 , pattern b is 3 -- 1,3 . when pattern a is 2 , pattern b is 3 . when pattern a is 4 , pattern b is 3 . when pattern a is 8 , pattern b is 3 . when pattern a is 16 , pattern -- this is like a tongue -- when pattern a is 16 , pattern b is 3 . when pattern a is 32 , pattern b is 3 . and you see , they all sit on a line . they all sit on this horizontal line , or at least the way that we 've drawn it . they all sit on this line that you probably ca n't see in yellow . so let me do it in this red color . they all sit on this line right over here . so this looks right . if we graph the pairs , the points will be on the same line . so i 'll go with that one . in pattern b , you can get from any term to the next by multiplying by a constant number . well , yeah , even though every term is the same term , but you can get from a 3 to a 3 by always multiplying by 1 . 1 is a constant number . so we 're just multiplying every term by 1 . so that also seems to be right . so all of these are right , except the second one . the next pair is n't 52 comma 3 . it 's going to be 64 comma 3 .
|
so there 's a couple of ways you can think about it . you could just say , pattern b 's always 3 . you could say pattern b starts at 3 , and we 're just adding 0 every time .
|
and pattern a always horizontal ?
|
we should talk a little more about newtons 's third law , because there are some deep misconceptions that many people have about this law . it seems simple , but it 's not nearly as simple as you might think . so people often phrase it as , for every action there 's an equal and opposite reaction . but that 's just way too vague to be useful . so a version that 's a little better , says that for every force , there 's an equal and opposite force . so this is a little better . the equal sign means that these forces are equal in magnitude . and this negative sign means they 're just different by the direction of the vector . so these are vectors , so this says that this pink vector f , has the opposite direction , but equal in magnitude to this green vector f. but to show you why this is still a little bit too vague , consider this , if this is all you knew about newtons 's third law , that for every force , there 's an equal and opposite force , you might wonder , if you were clever , you might be like , wait a minute , if for every force f , right , there 's got to be a force that 's equal and opposite . well why does n't that just mean that every force in the universe cancels ? should n't every force just cancel then , at that point ? does n't that just mean that there 's no acceleration that 's even possible ? because if i go and exert a force f on something , if there 's gon na be a force negative f , does n't that mean that no matter what force i put forward , it 's just gon na get cancelled ? and the answer no , and the reason it 's no is because these two forces are exerted on different objects . so you have to be careful . so the reason i say that this statement of newtons 's third law is still a little bit too vague , is because this is really on different objects . so if this is the force on object a , exerted by object b , then this force over here has to be the force on object b , exerted by object a . in other words , these forces down here are exerted on different objects . i 'm gon na move this over to this side . i 'm gon na move this over to here . let 's draw two different objects to show explicitly what i mean . so if there was some object a , so i put some object a in here . just wan na make sure there 's an object a . let 's say this is object a , and it had this green force exerted on it , f. so this object right here is a . well , there 's gon na be another object , object b . we 'll just make it another circle . so we 'll make it look like this . so here 's object b . and it 's gon na have this pink force , f , negative f exerted on it . so i 'm gon na call this object b . now we 're okay , now we know these forces ca n't cancel , and the reason these forces ca n't cancel , is cause they 're on two different objects . but when you just say that newtons 's third law , is that every force has an equal and opposite force , it 's not clear that it has to be on different objects . but it does have to be on different objects . so these newtons force law pairs , often times is called force pairs , or newton 's third law partner forces , are always on different objects . so the convention i 'm using is that the first letter represents the object that the force is on . so this a represents that this green force f this green force f , is on a and it 's exerted by b . and this shows that it 's exerted on b , because the first letter 's on the first one , and it 's exerted by the second object , a . so this pink force is exerted on b . this green force is exerted on a . they 're equal and opposite , they do not cancel , they can not cancel because they 're not on the same object . so that 's why these do n't cancel . and they are the same magnitude , even if the two objects are not the same size . this is another misconception , if object a is a planet , a big planet . or maybe a star , this is yellow , it looks like a star . let 's say this is some big star , and this is some smaller planet orbiting that star . this is not to scale , unless this planet was enormous . so this is some planet , but this planet could be hundreds , thousands of times , millions of times less massive than this star but it would still exert the same force . so if this star is pulling on the planet with this pink force negative f , then this planet has to be pulling on the star with this green force f and they have to have the same magnitude , even if they are different sizes . so people quote newtons 's third law , but sometimes they do n't really believe it . if i told you this planet was a million times less massive than this star , people would want to say that well , then the star obviously pulls more on the planet , than the planet pulls on the star . but that 's not true according to newtons 's third law . and newtons 's third law says that they have to be the same , even if they 're different sizes . so if this was the earth and this was the moon , the earth pulls on the moon , just as much as the moon pulls on the earth . and you might still object , you might say , wait that makes no sense , i know the star just basically sits there and the planet gets whipped around in a circle . how come this planet 's getting whipped around and the star 's just staying put ? that 's because , just because the forces are equal , that does n't mean that the result is equal . in other words , the forces could be equal , but the accelerations do n't have to be equal . acceleration is gon na be the net force divided by the mass . so even if the force is the same , you divide by that mass , you 'll get a different acceleration and that 's why the result of the force does not have to be the same , even though the forces do have to be the same , because of newtons 's third law . another misconception people sometimes make , is they think there might be a delay in the creation of this newtons 's third law partner force . and people think , maybe if i exert this first force fast enough , i can catch the universe sleeping , and there might be some sort of delay in the creation of this other force . but that 's not true , newtons 's third law is universal . no matter what the situation , no matter what the acceleration or non acceleration , or motion or no motion , whether one object is bigger or smaller , if their newtons 's third law partner forces , they are equal they are opposite and they are always equal and opposite , at every given moment in time . so even if i came in all guns a blazing , chuck norris style , trying to dropkick some wall . that does not look like the correct form for a drop kick . but even if i came in , flying at this wall , as soon as i start to make contact with the wall , i 'm gon na exert a force on the wall , and the wall has to exert a force back . so i 'd exert a force on the wall to the right . and this would be the force on the wall , by my foot . there 'd have to be an equal and opposite force instantly transmitted backwards , on my foot . so this would be the force on my foot , by the wall . this happens instantaneously , there is no delay . you ca n't kick this wall fast enough , for this other force to not be generated instantaneously . as soon as your foot starts to exert any force on the wall what so ever , the wall is gon na start exerting that same force back on your foot . so newtons 's third law is universal , but people still have trouble identifying these third law partner forces . so one of the best ways to do it , is by listing both objects , as soon as you list both objects , well to figure out where the partner force is , you can just reverse these labels . so i know over here , if one of my forces is the force on the wall by my foot , to find the partner force to this force , i can just reverse the labels and say it 's got ta be the force on my foot , by the wall , which i drew over here . so this is a great way to identify the third law partner forces , cause it 's not always obvious what force is the partner force . so to show you how this can be tricky , consider this example . say we got the ground and a table . so this example drives people crazy for some reason . if i 've got a box sitting on a table , we 'll call it box a . box a is gon na have forces exerted on it . one of those forces is gon na be the gravitational force . so the force of gravity is gon na pull straight down on box a , and if i were to ask you , what force is the third law partner force to this force of gravity , i 'm willing to bet a lot of people might say , well there 's an upwards force on box a , exerted by the table . and that 's true . and if this box a is just sitting here , not accelerating , these two forces are going to be equal and opposite . so it 's even more tempting to say that these two forces are equal and opposite because of the third law , but that 's not true . these two forces are equal and opposite because of the second law . the second law says if there 's no acceleration , then the net force has to be zero , the forces have to cancel . and that 's what 's happening here . these forces are equal and opposite , they 're canceling on box a . which is a way to know that they are not third law partner forces , cause third law partner forces are always exerted on different objects . they can never cancel if they 're third law partner forces . so what 's going on over here ? we 've got two forces that are canceling , that are equal and opposite , but they 're not third law partner forces , they 're partner forces are somewhere else . i have n't drawn their partner forces yet . so let 's try to figure out what they 're partner forces are . so let 's get rid of this , let 's come back to here , let 's slow it down to figure out what the partner force is , name the two objects interacting . so this force of gravity , i should n't be vague , i should call it the force on object a , our box a exerted by , well you ca n't just say gravity . gravity is not an object . so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is . the partner force can be found just by reversing these labels . so instead of the force on a by the earth , there 's got ta be an equal and opposite force , which is the force on the earth , by box a . so opposite means it has to point up . so it has to be an upward force . and that upward force has to be exerted on the earth , by box a , and this is kind of weird , because you may not have realized it , but if the earth is pulling down on a box , or you , that means you are pulling up on the earth . and this might seem ridiculous , i mean if you jump up , you jump up , you fall back down , you move around , but the earth just sits there . if your forces are equal , how come the earth does n't move around like you do . and again , it 's because just because the forces are the same , the acceleration does n't have to be the same . the mass of the earth is so big , compared to your mass , there 's basically no acceleration . even though the forces on you and the forces on the earth are the same . so these two are third law partner forces . these two are joined together forever . they have to be equal , no matter what happens , these two forces will always be equal . i do n't care if this box is accelerating or not accelerating , or that there 's motion or no motion . whether it 's hitting a wall , sitting on a table , falling through space , these two forces must always be equal and opposite , because of the third law . so how about this other force , this force that the table was exerting . so this is , the force on a by the table . so if i wan na label it correctly , i 'd call it the force on box a , exerted by the table . now finding the third law partner force is easy , i can just reverse these labels , and i 'd get that there must be , instead of an upwards force , a downwards force on the table , by a . so i 'm gon na have another force here on the table . it 's gon na be a downward force . downward force on the table by a , that 's the third law partner force to this upward force that the table is exerting . these two forces are also third law partner forces . these forces are going to be equal and opposite no matter what happens . this force on box a by the table . and this force on the table by box a must be equal no matter what happens , but the force on box a by the table , does not have to be equal and opposite to the force on a by the earth . it happens to be equal and opposite , in a case where there 's no acceleration . if we stuck this whole situation into an elevator , or a rocket that had some huge acceleration upwards , even if there 's acceleration upwards , these partner forces have to be equal . so the force on a by the table , and the force on the table by a will have to be equal . similarly the force on the earth by a , and the force on a by the earth have to be equal . but no longer will these two forces have to be equal , cause they 're not partner forces . they might be equal and opposite in some circumstances , but they do n't always have to be equal and opposite . if we 're accelerating upwards , this upward force on the box , must be bigger than the downwards force on the box . so these wo n't be equal . recapping quickly , newtons 's third law is a statement about the forces on two different objects . and because it 's about two different objects , those forces can never cancel . to find the newtons 's third law partner force , just reverse the label after you 've identified the two objects that are interacting . the third law partner forces have to be equal in magnitude , even if one object is larger than the other , or has more charge or any property that might seem like it would convey more force , than another object . if those are the two objects interacting , their forces must be of equal magnitude and opposite directions , the forces instantaneously generated this partner forces . and be careful , some forces might seem like partner forces , and might be equal and opposite , but they 're not necessarily third law partner forces . they made just be equal and opposite for other reasons .
|
so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is .
|
why is the force instantaneous ?
|
we should talk a little more about newtons 's third law , because there are some deep misconceptions that many people have about this law . it seems simple , but it 's not nearly as simple as you might think . so people often phrase it as , for every action there 's an equal and opposite reaction . but that 's just way too vague to be useful . so a version that 's a little better , says that for every force , there 's an equal and opposite force . so this is a little better . the equal sign means that these forces are equal in magnitude . and this negative sign means they 're just different by the direction of the vector . so these are vectors , so this says that this pink vector f , has the opposite direction , but equal in magnitude to this green vector f. but to show you why this is still a little bit too vague , consider this , if this is all you knew about newtons 's third law , that for every force , there 's an equal and opposite force , you might wonder , if you were clever , you might be like , wait a minute , if for every force f , right , there 's got to be a force that 's equal and opposite . well why does n't that just mean that every force in the universe cancels ? should n't every force just cancel then , at that point ? does n't that just mean that there 's no acceleration that 's even possible ? because if i go and exert a force f on something , if there 's gon na be a force negative f , does n't that mean that no matter what force i put forward , it 's just gon na get cancelled ? and the answer no , and the reason it 's no is because these two forces are exerted on different objects . so you have to be careful . so the reason i say that this statement of newtons 's third law is still a little bit too vague , is because this is really on different objects . so if this is the force on object a , exerted by object b , then this force over here has to be the force on object b , exerted by object a . in other words , these forces down here are exerted on different objects . i 'm gon na move this over to this side . i 'm gon na move this over to here . let 's draw two different objects to show explicitly what i mean . so if there was some object a , so i put some object a in here . just wan na make sure there 's an object a . let 's say this is object a , and it had this green force exerted on it , f. so this object right here is a . well , there 's gon na be another object , object b . we 'll just make it another circle . so we 'll make it look like this . so here 's object b . and it 's gon na have this pink force , f , negative f exerted on it . so i 'm gon na call this object b . now we 're okay , now we know these forces ca n't cancel , and the reason these forces ca n't cancel , is cause they 're on two different objects . but when you just say that newtons 's third law , is that every force has an equal and opposite force , it 's not clear that it has to be on different objects . but it does have to be on different objects . so these newtons force law pairs , often times is called force pairs , or newton 's third law partner forces , are always on different objects . so the convention i 'm using is that the first letter represents the object that the force is on . so this a represents that this green force f this green force f , is on a and it 's exerted by b . and this shows that it 's exerted on b , because the first letter 's on the first one , and it 's exerted by the second object , a . so this pink force is exerted on b . this green force is exerted on a . they 're equal and opposite , they do not cancel , they can not cancel because they 're not on the same object . so that 's why these do n't cancel . and they are the same magnitude , even if the two objects are not the same size . this is another misconception , if object a is a planet , a big planet . or maybe a star , this is yellow , it looks like a star . let 's say this is some big star , and this is some smaller planet orbiting that star . this is not to scale , unless this planet was enormous . so this is some planet , but this planet could be hundreds , thousands of times , millions of times less massive than this star but it would still exert the same force . so if this star is pulling on the planet with this pink force negative f , then this planet has to be pulling on the star with this green force f and they have to have the same magnitude , even if they are different sizes . so people quote newtons 's third law , but sometimes they do n't really believe it . if i told you this planet was a million times less massive than this star , people would want to say that well , then the star obviously pulls more on the planet , than the planet pulls on the star . but that 's not true according to newtons 's third law . and newtons 's third law says that they have to be the same , even if they 're different sizes . so if this was the earth and this was the moon , the earth pulls on the moon , just as much as the moon pulls on the earth . and you might still object , you might say , wait that makes no sense , i know the star just basically sits there and the planet gets whipped around in a circle . how come this planet 's getting whipped around and the star 's just staying put ? that 's because , just because the forces are equal , that does n't mean that the result is equal . in other words , the forces could be equal , but the accelerations do n't have to be equal . acceleration is gon na be the net force divided by the mass . so even if the force is the same , you divide by that mass , you 'll get a different acceleration and that 's why the result of the force does not have to be the same , even though the forces do have to be the same , because of newtons 's third law . another misconception people sometimes make , is they think there might be a delay in the creation of this newtons 's third law partner force . and people think , maybe if i exert this first force fast enough , i can catch the universe sleeping , and there might be some sort of delay in the creation of this other force . but that 's not true , newtons 's third law is universal . no matter what the situation , no matter what the acceleration or non acceleration , or motion or no motion , whether one object is bigger or smaller , if their newtons 's third law partner forces , they are equal they are opposite and they are always equal and opposite , at every given moment in time . so even if i came in all guns a blazing , chuck norris style , trying to dropkick some wall . that does not look like the correct form for a drop kick . but even if i came in , flying at this wall , as soon as i start to make contact with the wall , i 'm gon na exert a force on the wall , and the wall has to exert a force back . so i 'd exert a force on the wall to the right . and this would be the force on the wall , by my foot . there 'd have to be an equal and opposite force instantly transmitted backwards , on my foot . so this would be the force on my foot , by the wall . this happens instantaneously , there is no delay . you ca n't kick this wall fast enough , for this other force to not be generated instantaneously . as soon as your foot starts to exert any force on the wall what so ever , the wall is gon na start exerting that same force back on your foot . so newtons 's third law is universal , but people still have trouble identifying these third law partner forces . so one of the best ways to do it , is by listing both objects , as soon as you list both objects , well to figure out where the partner force is , you can just reverse these labels . so i know over here , if one of my forces is the force on the wall by my foot , to find the partner force to this force , i can just reverse the labels and say it 's got ta be the force on my foot , by the wall , which i drew over here . so this is a great way to identify the third law partner forces , cause it 's not always obvious what force is the partner force . so to show you how this can be tricky , consider this example . say we got the ground and a table . so this example drives people crazy for some reason . if i 've got a box sitting on a table , we 'll call it box a . box a is gon na have forces exerted on it . one of those forces is gon na be the gravitational force . so the force of gravity is gon na pull straight down on box a , and if i were to ask you , what force is the third law partner force to this force of gravity , i 'm willing to bet a lot of people might say , well there 's an upwards force on box a , exerted by the table . and that 's true . and if this box a is just sitting here , not accelerating , these two forces are going to be equal and opposite . so it 's even more tempting to say that these two forces are equal and opposite because of the third law , but that 's not true . these two forces are equal and opposite because of the second law . the second law says if there 's no acceleration , then the net force has to be zero , the forces have to cancel . and that 's what 's happening here . these forces are equal and opposite , they 're canceling on box a . which is a way to know that they are not third law partner forces , cause third law partner forces are always exerted on different objects . they can never cancel if they 're third law partner forces . so what 's going on over here ? we 've got two forces that are canceling , that are equal and opposite , but they 're not third law partner forces , they 're partner forces are somewhere else . i have n't drawn their partner forces yet . so let 's try to figure out what they 're partner forces are . so let 's get rid of this , let 's come back to here , let 's slow it down to figure out what the partner force is , name the two objects interacting . so this force of gravity , i should n't be vague , i should call it the force on object a , our box a exerted by , well you ca n't just say gravity . gravity is not an object . so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is . the partner force can be found just by reversing these labels . so instead of the force on a by the earth , there 's got ta be an equal and opposite force , which is the force on the earth , by box a . so opposite means it has to point up . so it has to be an upward force . and that upward force has to be exerted on the earth , by box a , and this is kind of weird , because you may not have realized it , but if the earth is pulling down on a box , or you , that means you are pulling up on the earth . and this might seem ridiculous , i mean if you jump up , you jump up , you fall back down , you move around , but the earth just sits there . if your forces are equal , how come the earth does n't move around like you do . and again , it 's because just because the forces are the same , the acceleration does n't have to be the same . the mass of the earth is so big , compared to your mass , there 's basically no acceleration . even though the forces on you and the forces on the earth are the same . so these two are third law partner forces . these two are joined together forever . they have to be equal , no matter what happens , these two forces will always be equal . i do n't care if this box is accelerating or not accelerating , or that there 's motion or no motion . whether it 's hitting a wall , sitting on a table , falling through space , these two forces must always be equal and opposite , because of the third law . so how about this other force , this force that the table was exerting . so this is , the force on a by the table . so if i wan na label it correctly , i 'd call it the force on box a , exerted by the table . now finding the third law partner force is easy , i can just reverse these labels , and i 'd get that there must be , instead of an upwards force , a downwards force on the table , by a . so i 'm gon na have another force here on the table . it 's gon na be a downward force . downward force on the table by a , that 's the third law partner force to this upward force that the table is exerting . these two forces are also third law partner forces . these forces are going to be equal and opposite no matter what happens . this force on box a by the table . and this force on the table by box a must be equal no matter what happens , but the force on box a by the table , does not have to be equal and opposite to the force on a by the earth . it happens to be equal and opposite , in a case where there 's no acceleration . if we stuck this whole situation into an elevator , or a rocket that had some huge acceleration upwards , even if there 's acceleration upwards , these partner forces have to be equal . so the force on a by the table , and the force on the table by a will have to be equal . similarly the force on the earth by a , and the force on a by the earth have to be equal . but no longer will these two forces have to be equal , cause they 're not partner forces . they might be equal and opposite in some circumstances , but they do n't always have to be equal and opposite . if we 're accelerating upwards , this upward force on the box , must be bigger than the downwards force on the box . so these wo n't be equal . recapping quickly , newtons 's third law is a statement about the forces on two different objects . and because it 's about two different objects , those forces can never cancel . to find the newtons 's third law partner force , just reverse the label after you 've identified the two objects that are interacting . the third law partner forces have to be equal in magnitude , even if one object is larger than the other , or has more charge or any property that might seem like it would convey more force , than another object . if those are the two objects interacting , their forces must be of equal magnitude and opposite directions , the forces instantaneously generated this partner forces . and be careful , some forces might seem like partner forces , and might be equal and opposite , but they 're not necessarily third law partner forces . they made just be equal and opposite for other reasons .
|
no matter what the situation , no matter what the acceleration or non acceleration , or motion or no motion , whether one object is bigger or smaller , if their newtons 's third law partner forces , they are equal they are opposite and they are always equal and opposite , at every given moment in time . so even if i came in all guns a blazing , chuck norris style , trying to dropkick some wall . that does not look like the correct form for a drop kick .
|
why does the wall not generate constant force , even without chuck norris drop kicking it ?
|
we should talk a little more about newtons 's third law , because there are some deep misconceptions that many people have about this law . it seems simple , but it 's not nearly as simple as you might think . so people often phrase it as , for every action there 's an equal and opposite reaction . but that 's just way too vague to be useful . so a version that 's a little better , says that for every force , there 's an equal and opposite force . so this is a little better . the equal sign means that these forces are equal in magnitude . and this negative sign means they 're just different by the direction of the vector . so these are vectors , so this says that this pink vector f , has the opposite direction , but equal in magnitude to this green vector f. but to show you why this is still a little bit too vague , consider this , if this is all you knew about newtons 's third law , that for every force , there 's an equal and opposite force , you might wonder , if you were clever , you might be like , wait a minute , if for every force f , right , there 's got to be a force that 's equal and opposite . well why does n't that just mean that every force in the universe cancels ? should n't every force just cancel then , at that point ? does n't that just mean that there 's no acceleration that 's even possible ? because if i go and exert a force f on something , if there 's gon na be a force negative f , does n't that mean that no matter what force i put forward , it 's just gon na get cancelled ? and the answer no , and the reason it 's no is because these two forces are exerted on different objects . so you have to be careful . so the reason i say that this statement of newtons 's third law is still a little bit too vague , is because this is really on different objects . so if this is the force on object a , exerted by object b , then this force over here has to be the force on object b , exerted by object a . in other words , these forces down here are exerted on different objects . i 'm gon na move this over to this side . i 'm gon na move this over to here . let 's draw two different objects to show explicitly what i mean . so if there was some object a , so i put some object a in here . just wan na make sure there 's an object a . let 's say this is object a , and it had this green force exerted on it , f. so this object right here is a . well , there 's gon na be another object , object b . we 'll just make it another circle . so we 'll make it look like this . so here 's object b . and it 's gon na have this pink force , f , negative f exerted on it . so i 'm gon na call this object b . now we 're okay , now we know these forces ca n't cancel , and the reason these forces ca n't cancel , is cause they 're on two different objects . but when you just say that newtons 's third law , is that every force has an equal and opposite force , it 's not clear that it has to be on different objects . but it does have to be on different objects . so these newtons force law pairs , often times is called force pairs , or newton 's third law partner forces , are always on different objects . so the convention i 'm using is that the first letter represents the object that the force is on . so this a represents that this green force f this green force f , is on a and it 's exerted by b . and this shows that it 's exerted on b , because the first letter 's on the first one , and it 's exerted by the second object , a . so this pink force is exerted on b . this green force is exerted on a . they 're equal and opposite , they do not cancel , they can not cancel because they 're not on the same object . so that 's why these do n't cancel . and they are the same magnitude , even if the two objects are not the same size . this is another misconception , if object a is a planet , a big planet . or maybe a star , this is yellow , it looks like a star . let 's say this is some big star , and this is some smaller planet orbiting that star . this is not to scale , unless this planet was enormous . so this is some planet , but this planet could be hundreds , thousands of times , millions of times less massive than this star but it would still exert the same force . so if this star is pulling on the planet with this pink force negative f , then this planet has to be pulling on the star with this green force f and they have to have the same magnitude , even if they are different sizes . so people quote newtons 's third law , but sometimes they do n't really believe it . if i told you this planet was a million times less massive than this star , people would want to say that well , then the star obviously pulls more on the planet , than the planet pulls on the star . but that 's not true according to newtons 's third law . and newtons 's third law says that they have to be the same , even if they 're different sizes . so if this was the earth and this was the moon , the earth pulls on the moon , just as much as the moon pulls on the earth . and you might still object , you might say , wait that makes no sense , i know the star just basically sits there and the planet gets whipped around in a circle . how come this planet 's getting whipped around and the star 's just staying put ? that 's because , just because the forces are equal , that does n't mean that the result is equal . in other words , the forces could be equal , but the accelerations do n't have to be equal . acceleration is gon na be the net force divided by the mass . so even if the force is the same , you divide by that mass , you 'll get a different acceleration and that 's why the result of the force does not have to be the same , even though the forces do have to be the same , because of newtons 's third law . another misconception people sometimes make , is they think there might be a delay in the creation of this newtons 's third law partner force . and people think , maybe if i exert this first force fast enough , i can catch the universe sleeping , and there might be some sort of delay in the creation of this other force . but that 's not true , newtons 's third law is universal . no matter what the situation , no matter what the acceleration or non acceleration , or motion or no motion , whether one object is bigger or smaller , if their newtons 's third law partner forces , they are equal they are opposite and they are always equal and opposite , at every given moment in time . so even if i came in all guns a blazing , chuck norris style , trying to dropkick some wall . that does not look like the correct form for a drop kick . but even if i came in , flying at this wall , as soon as i start to make contact with the wall , i 'm gon na exert a force on the wall , and the wall has to exert a force back . so i 'd exert a force on the wall to the right . and this would be the force on the wall , by my foot . there 'd have to be an equal and opposite force instantly transmitted backwards , on my foot . so this would be the force on my foot , by the wall . this happens instantaneously , there is no delay . you ca n't kick this wall fast enough , for this other force to not be generated instantaneously . as soon as your foot starts to exert any force on the wall what so ever , the wall is gon na start exerting that same force back on your foot . so newtons 's third law is universal , but people still have trouble identifying these third law partner forces . so one of the best ways to do it , is by listing both objects , as soon as you list both objects , well to figure out where the partner force is , you can just reverse these labels . so i know over here , if one of my forces is the force on the wall by my foot , to find the partner force to this force , i can just reverse the labels and say it 's got ta be the force on my foot , by the wall , which i drew over here . so this is a great way to identify the third law partner forces , cause it 's not always obvious what force is the partner force . so to show you how this can be tricky , consider this example . say we got the ground and a table . so this example drives people crazy for some reason . if i 've got a box sitting on a table , we 'll call it box a . box a is gon na have forces exerted on it . one of those forces is gon na be the gravitational force . so the force of gravity is gon na pull straight down on box a , and if i were to ask you , what force is the third law partner force to this force of gravity , i 'm willing to bet a lot of people might say , well there 's an upwards force on box a , exerted by the table . and that 's true . and if this box a is just sitting here , not accelerating , these two forces are going to be equal and opposite . so it 's even more tempting to say that these two forces are equal and opposite because of the third law , but that 's not true . these two forces are equal and opposite because of the second law . the second law says if there 's no acceleration , then the net force has to be zero , the forces have to cancel . and that 's what 's happening here . these forces are equal and opposite , they 're canceling on box a . which is a way to know that they are not third law partner forces , cause third law partner forces are always exerted on different objects . they can never cancel if they 're third law partner forces . so what 's going on over here ? we 've got two forces that are canceling , that are equal and opposite , but they 're not third law partner forces , they 're partner forces are somewhere else . i have n't drawn their partner forces yet . so let 's try to figure out what they 're partner forces are . so let 's get rid of this , let 's come back to here , let 's slow it down to figure out what the partner force is , name the two objects interacting . so this force of gravity , i should n't be vague , i should call it the force on object a , our box a exerted by , well you ca n't just say gravity . gravity is not an object . so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is . the partner force can be found just by reversing these labels . so instead of the force on a by the earth , there 's got ta be an equal and opposite force , which is the force on the earth , by box a . so opposite means it has to point up . so it has to be an upward force . and that upward force has to be exerted on the earth , by box a , and this is kind of weird , because you may not have realized it , but if the earth is pulling down on a box , or you , that means you are pulling up on the earth . and this might seem ridiculous , i mean if you jump up , you jump up , you fall back down , you move around , but the earth just sits there . if your forces are equal , how come the earth does n't move around like you do . and again , it 's because just because the forces are the same , the acceleration does n't have to be the same . the mass of the earth is so big , compared to your mass , there 's basically no acceleration . even though the forces on you and the forces on the earth are the same . so these two are third law partner forces . these two are joined together forever . they have to be equal , no matter what happens , these two forces will always be equal . i do n't care if this box is accelerating or not accelerating , or that there 's motion or no motion . whether it 's hitting a wall , sitting on a table , falling through space , these two forces must always be equal and opposite , because of the third law . so how about this other force , this force that the table was exerting . so this is , the force on a by the table . so if i wan na label it correctly , i 'd call it the force on box a , exerted by the table . now finding the third law partner force is easy , i can just reverse these labels , and i 'd get that there must be , instead of an upwards force , a downwards force on the table , by a . so i 'm gon na have another force here on the table . it 's gon na be a downward force . downward force on the table by a , that 's the third law partner force to this upward force that the table is exerting . these two forces are also third law partner forces . these forces are going to be equal and opposite no matter what happens . this force on box a by the table . and this force on the table by box a must be equal no matter what happens , but the force on box a by the table , does not have to be equal and opposite to the force on a by the earth . it happens to be equal and opposite , in a case where there 's no acceleration . if we stuck this whole situation into an elevator , or a rocket that had some huge acceleration upwards , even if there 's acceleration upwards , these partner forces have to be equal . so the force on a by the table , and the force on the table by a will have to be equal . similarly the force on the earth by a , and the force on a by the earth have to be equal . but no longer will these two forces have to be equal , cause they 're not partner forces . they might be equal and opposite in some circumstances , but they do n't always have to be equal and opposite . if we 're accelerating upwards , this upward force on the box , must be bigger than the downwards force on the box . so these wo n't be equal . recapping quickly , newtons 's third law is a statement about the forces on two different objects . and because it 's about two different objects , those forces can never cancel . to find the newtons 's third law partner force , just reverse the label after you 've identified the two objects that are interacting . the third law partner forces have to be equal in magnitude , even if one object is larger than the other , or has more charge or any property that might seem like it would convey more force , than another object . if those are the two objects interacting , their forces must be of equal magnitude and opposite directions , the forces instantaneously generated this partner forces . and be careful , some forces might seem like partner forces , and might be equal and opposite , but they 're not necessarily third law partner forces . they made just be equal and opposite for other reasons .
|
whether it 's hitting a wall , sitting on a table , falling through space , these two forces must always be equal and opposite , because of the third law . so how about this other force , this force that the table was exerting . so this is , the force on a by the table .
|
it seems to me that there is more going on than just the wall exerting a force ... why is it only exerting this force at the instant when chuck norris comes into contact with it ?
|
we should talk a little more about newtons 's third law , because there are some deep misconceptions that many people have about this law . it seems simple , but it 's not nearly as simple as you might think . so people often phrase it as , for every action there 's an equal and opposite reaction . but that 's just way too vague to be useful . so a version that 's a little better , says that for every force , there 's an equal and opposite force . so this is a little better . the equal sign means that these forces are equal in magnitude . and this negative sign means they 're just different by the direction of the vector . so these are vectors , so this says that this pink vector f , has the opposite direction , but equal in magnitude to this green vector f. but to show you why this is still a little bit too vague , consider this , if this is all you knew about newtons 's third law , that for every force , there 's an equal and opposite force , you might wonder , if you were clever , you might be like , wait a minute , if for every force f , right , there 's got to be a force that 's equal and opposite . well why does n't that just mean that every force in the universe cancels ? should n't every force just cancel then , at that point ? does n't that just mean that there 's no acceleration that 's even possible ? because if i go and exert a force f on something , if there 's gon na be a force negative f , does n't that mean that no matter what force i put forward , it 's just gon na get cancelled ? and the answer no , and the reason it 's no is because these two forces are exerted on different objects . so you have to be careful . so the reason i say that this statement of newtons 's third law is still a little bit too vague , is because this is really on different objects . so if this is the force on object a , exerted by object b , then this force over here has to be the force on object b , exerted by object a . in other words , these forces down here are exerted on different objects . i 'm gon na move this over to this side . i 'm gon na move this over to here . let 's draw two different objects to show explicitly what i mean . so if there was some object a , so i put some object a in here . just wan na make sure there 's an object a . let 's say this is object a , and it had this green force exerted on it , f. so this object right here is a . well , there 's gon na be another object , object b . we 'll just make it another circle . so we 'll make it look like this . so here 's object b . and it 's gon na have this pink force , f , negative f exerted on it . so i 'm gon na call this object b . now we 're okay , now we know these forces ca n't cancel , and the reason these forces ca n't cancel , is cause they 're on two different objects . but when you just say that newtons 's third law , is that every force has an equal and opposite force , it 's not clear that it has to be on different objects . but it does have to be on different objects . so these newtons force law pairs , often times is called force pairs , or newton 's third law partner forces , are always on different objects . so the convention i 'm using is that the first letter represents the object that the force is on . so this a represents that this green force f this green force f , is on a and it 's exerted by b . and this shows that it 's exerted on b , because the first letter 's on the first one , and it 's exerted by the second object , a . so this pink force is exerted on b . this green force is exerted on a . they 're equal and opposite , they do not cancel , they can not cancel because they 're not on the same object . so that 's why these do n't cancel . and they are the same magnitude , even if the two objects are not the same size . this is another misconception , if object a is a planet , a big planet . or maybe a star , this is yellow , it looks like a star . let 's say this is some big star , and this is some smaller planet orbiting that star . this is not to scale , unless this planet was enormous . so this is some planet , but this planet could be hundreds , thousands of times , millions of times less massive than this star but it would still exert the same force . so if this star is pulling on the planet with this pink force negative f , then this planet has to be pulling on the star with this green force f and they have to have the same magnitude , even if they are different sizes . so people quote newtons 's third law , but sometimes they do n't really believe it . if i told you this planet was a million times less massive than this star , people would want to say that well , then the star obviously pulls more on the planet , than the planet pulls on the star . but that 's not true according to newtons 's third law . and newtons 's third law says that they have to be the same , even if they 're different sizes . so if this was the earth and this was the moon , the earth pulls on the moon , just as much as the moon pulls on the earth . and you might still object , you might say , wait that makes no sense , i know the star just basically sits there and the planet gets whipped around in a circle . how come this planet 's getting whipped around and the star 's just staying put ? that 's because , just because the forces are equal , that does n't mean that the result is equal . in other words , the forces could be equal , but the accelerations do n't have to be equal . acceleration is gon na be the net force divided by the mass . so even if the force is the same , you divide by that mass , you 'll get a different acceleration and that 's why the result of the force does not have to be the same , even though the forces do have to be the same , because of newtons 's third law . another misconception people sometimes make , is they think there might be a delay in the creation of this newtons 's third law partner force . and people think , maybe if i exert this first force fast enough , i can catch the universe sleeping , and there might be some sort of delay in the creation of this other force . but that 's not true , newtons 's third law is universal . no matter what the situation , no matter what the acceleration or non acceleration , or motion or no motion , whether one object is bigger or smaller , if their newtons 's third law partner forces , they are equal they are opposite and they are always equal and opposite , at every given moment in time . so even if i came in all guns a blazing , chuck norris style , trying to dropkick some wall . that does not look like the correct form for a drop kick . but even if i came in , flying at this wall , as soon as i start to make contact with the wall , i 'm gon na exert a force on the wall , and the wall has to exert a force back . so i 'd exert a force on the wall to the right . and this would be the force on the wall , by my foot . there 'd have to be an equal and opposite force instantly transmitted backwards , on my foot . so this would be the force on my foot , by the wall . this happens instantaneously , there is no delay . you ca n't kick this wall fast enough , for this other force to not be generated instantaneously . as soon as your foot starts to exert any force on the wall what so ever , the wall is gon na start exerting that same force back on your foot . so newtons 's third law is universal , but people still have trouble identifying these third law partner forces . so one of the best ways to do it , is by listing both objects , as soon as you list both objects , well to figure out where the partner force is , you can just reverse these labels . so i know over here , if one of my forces is the force on the wall by my foot , to find the partner force to this force , i can just reverse the labels and say it 's got ta be the force on my foot , by the wall , which i drew over here . so this is a great way to identify the third law partner forces , cause it 's not always obvious what force is the partner force . so to show you how this can be tricky , consider this example . say we got the ground and a table . so this example drives people crazy for some reason . if i 've got a box sitting on a table , we 'll call it box a . box a is gon na have forces exerted on it . one of those forces is gon na be the gravitational force . so the force of gravity is gon na pull straight down on box a , and if i were to ask you , what force is the third law partner force to this force of gravity , i 'm willing to bet a lot of people might say , well there 's an upwards force on box a , exerted by the table . and that 's true . and if this box a is just sitting here , not accelerating , these two forces are going to be equal and opposite . so it 's even more tempting to say that these two forces are equal and opposite because of the third law , but that 's not true . these two forces are equal and opposite because of the second law . the second law says if there 's no acceleration , then the net force has to be zero , the forces have to cancel . and that 's what 's happening here . these forces are equal and opposite , they 're canceling on box a . which is a way to know that they are not third law partner forces , cause third law partner forces are always exerted on different objects . they can never cancel if they 're third law partner forces . so what 's going on over here ? we 've got two forces that are canceling , that are equal and opposite , but they 're not third law partner forces , they 're partner forces are somewhere else . i have n't drawn their partner forces yet . so let 's try to figure out what they 're partner forces are . so let 's get rid of this , let 's come back to here , let 's slow it down to figure out what the partner force is , name the two objects interacting . so this force of gravity , i should n't be vague , i should call it the force on object a , our box a exerted by , well you ca n't just say gravity . gravity is not an object . so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is . the partner force can be found just by reversing these labels . so instead of the force on a by the earth , there 's got ta be an equal and opposite force , which is the force on the earth , by box a . so opposite means it has to point up . so it has to be an upward force . and that upward force has to be exerted on the earth , by box a , and this is kind of weird , because you may not have realized it , but if the earth is pulling down on a box , or you , that means you are pulling up on the earth . and this might seem ridiculous , i mean if you jump up , you jump up , you fall back down , you move around , but the earth just sits there . if your forces are equal , how come the earth does n't move around like you do . and again , it 's because just because the forces are the same , the acceleration does n't have to be the same . the mass of the earth is so big , compared to your mass , there 's basically no acceleration . even though the forces on you and the forces on the earth are the same . so these two are third law partner forces . these two are joined together forever . they have to be equal , no matter what happens , these two forces will always be equal . i do n't care if this box is accelerating or not accelerating , or that there 's motion or no motion . whether it 's hitting a wall , sitting on a table , falling through space , these two forces must always be equal and opposite , because of the third law . so how about this other force , this force that the table was exerting . so this is , the force on a by the table . so if i wan na label it correctly , i 'd call it the force on box a , exerted by the table . now finding the third law partner force is easy , i can just reverse these labels , and i 'd get that there must be , instead of an upwards force , a downwards force on the table , by a . so i 'm gon na have another force here on the table . it 's gon na be a downward force . downward force on the table by a , that 's the third law partner force to this upward force that the table is exerting . these two forces are also third law partner forces . these forces are going to be equal and opposite no matter what happens . this force on box a by the table . and this force on the table by box a must be equal no matter what happens , but the force on box a by the table , does not have to be equal and opposite to the force on a by the earth . it happens to be equal and opposite , in a case where there 's no acceleration . if we stuck this whole situation into an elevator , or a rocket that had some huge acceleration upwards , even if there 's acceleration upwards , these partner forces have to be equal . so the force on a by the table , and the force on the table by a will have to be equal . similarly the force on the earth by a , and the force on a by the earth have to be equal . but no longer will these two forces have to be equal , cause they 're not partner forces . they might be equal and opposite in some circumstances , but they do n't always have to be equal and opposite . if we 're accelerating upwards , this upward force on the box , must be bigger than the downwards force on the box . so these wo n't be equal . recapping quickly , newtons 's third law is a statement about the forces on two different objects . and because it 's about two different objects , those forces can never cancel . to find the newtons 's third law partner force , just reverse the label after you 've identified the two objects that are interacting . the third law partner forces have to be equal in magnitude , even if one object is larger than the other , or has more charge or any property that might seem like it would convey more force , than another object . if those are the two objects interacting , their forces must be of equal magnitude and opposite directions , the forces instantaneously generated this partner forces . and be careful , some forces might seem like partner forces , and might be equal and opposite , but they 're not necessarily third law partner forces . they made just be equal and opposite for other reasons .
|
that does not look like the correct form for a drop kick . but even if i came in , flying at this wall , as soon as i start to make contact with the wall , i 'm gon na exert a force on the wall , and the wall has to exert a force back . so i 'd exert a force on the wall to the right .
|
also ... why does the wall break ?
|
we should talk a little more about newtons 's third law , because there are some deep misconceptions that many people have about this law . it seems simple , but it 's not nearly as simple as you might think . so people often phrase it as , for every action there 's an equal and opposite reaction . but that 's just way too vague to be useful . so a version that 's a little better , says that for every force , there 's an equal and opposite force . so this is a little better . the equal sign means that these forces are equal in magnitude . and this negative sign means they 're just different by the direction of the vector . so these are vectors , so this says that this pink vector f , has the opposite direction , but equal in magnitude to this green vector f. but to show you why this is still a little bit too vague , consider this , if this is all you knew about newtons 's third law , that for every force , there 's an equal and opposite force , you might wonder , if you were clever , you might be like , wait a minute , if for every force f , right , there 's got to be a force that 's equal and opposite . well why does n't that just mean that every force in the universe cancels ? should n't every force just cancel then , at that point ? does n't that just mean that there 's no acceleration that 's even possible ? because if i go and exert a force f on something , if there 's gon na be a force negative f , does n't that mean that no matter what force i put forward , it 's just gon na get cancelled ? and the answer no , and the reason it 's no is because these two forces are exerted on different objects . so you have to be careful . so the reason i say that this statement of newtons 's third law is still a little bit too vague , is because this is really on different objects . so if this is the force on object a , exerted by object b , then this force over here has to be the force on object b , exerted by object a . in other words , these forces down here are exerted on different objects . i 'm gon na move this over to this side . i 'm gon na move this over to here . let 's draw two different objects to show explicitly what i mean . so if there was some object a , so i put some object a in here . just wan na make sure there 's an object a . let 's say this is object a , and it had this green force exerted on it , f. so this object right here is a . well , there 's gon na be another object , object b . we 'll just make it another circle . so we 'll make it look like this . so here 's object b . and it 's gon na have this pink force , f , negative f exerted on it . so i 'm gon na call this object b . now we 're okay , now we know these forces ca n't cancel , and the reason these forces ca n't cancel , is cause they 're on two different objects . but when you just say that newtons 's third law , is that every force has an equal and opposite force , it 's not clear that it has to be on different objects . but it does have to be on different objects . so these newtons force law pairs , often times is called force pairs , or newton 's third law partner forces , are always on different objects . so the convention i 'm using is that the first letter represents the object that the force is on . so this a represents that this green force f this green force f , is on a and it 's exerted by b . and this shows that it 's exerted on b , because the first letter 's on the first one , and it 's exerted by the second object , a . so this pink force is exerted on b . this green force is exerted on a . they 're equal and opposite , they do not cancel , they can not cancel because they 're not on the same object . so that 's why these do n't cancel . and they are the same magnitude , even if the two objects are not the same size . this is another misconception , if object a is a planet , a big planet . or maybe a star , this is yellow , it looks like a star . let 's say this is some big star , and this is some smaller planet orbiting that star . this is not to scale , unless this planet was enormous . so this is some planet , but this planet could be hundreds , thousands of times , millions of times less massive than this star but it would still exert the same force . so if this star is pulling on the planet with this pink force negative f , then this planet has to be pulling on the star with this green force f and they have to have the same magnitude , even if they are different sizes . so people quote newtons 's third law , but sometimes they do n't really believe it . if i told you this planet was a million times less massive than this star , people would want to say that well , then the star obviously pulls more on the planet , than the planet pulls on the star . but that 's not true according to newtons 's third law . and newtons 's third law says that they have to be the same , even if they 're different sizes . so if this was the earth and this was the moon , the earth pulls on the moon , just as much as the moon pulls on the earth . and you might still object , you might say , wait that makes no sense , i know the star just basically sits there and the planet gets whipped around in a circle . how come this planet 's getting whipped around and the star 's just staying put ? that 's because , just because the forces are equal , that does n't mean that the result is equal . in other words , the forces could be equal , but the accelerations do n't have to be equal . acceleration is gon na be the net force divided by the mass . so even if the force is the same , you divide by that mass , you 'll get a different acceleration and that 's why the result of the force does not have to be the same , even though the forces do have to be the same , because of newtons 's third law . another misconception people sometimes make , is they think there might be a delay in the creation of this newtons 's third law partner force . and people think , maybe if i exert this first force fast enough , i can catch the universe sleeping , and there might be some sort of delay in the creation of this other force . but that 's not true , newtons 's third law is universal . no matter what the situation , no matter what the acceleration or non acceleration , or motion or no motion , whether one object is bigger or smaller , if their newtons 's third law partner forces , they are equal they are opposite and they are always equal and opposite , at every given moment in time . so even if i came in all guns a blazing , chuck norris style , trying to dropkick some wall . that does not look like the correct form for a drop kick . but even if i came in , flying at this wall , as soon as i start to make contact with the wall , i 'm gon na exert a force on the wall , and the wall has to exert a force back . so i 'd exert a force on the wall to the right . and this would be the force on the wall , by my foot . there 'd have to be an equal and opposite force instantly transmitted backwards , on my foot . so this would be the force on my foot , by the wall . this happens instantaneously , there is no delay . you ca n't kick this wall fast enough , for this other force to not be generated instantaneously . as soon as your foot starts to exert any force on the wall what so ever , the wall is gon na start exerting that same force back on your foot . so newtons 's third law is universal , but people still have trouble identifying these third law partner forces . so one of the best ways to do it , is by listing both objects , as soon as you list both objects , well to figure out where the partner force is , you can just reverse these labels . so i know over here , if one of my forces is the force on the wall by my foot , to find the partner force to this force , i can just reverse the labels and say it 's got ta be the force on my foot , by the wall , which i drew over here . so this is a great way to identify the third law partner forces , cause it 's not always obvious what force is the partner force . so to show you how this can be tricky , consider this example . say we got the ground and a table . so this example drives people crazy for some reason . if i 've got a box sitting on a table , we 'll call it box a . box a is gon na have forces exerted on it . one of those forces is gon na be the gravitational force . so the force of gravity is gon na pull straight down on box a , and if i were to ask you , what force is the third law partner force to this force of gravity , i 'm willing to bet a lot of people might say , well there 's an upwards force on box a , exerted by the table . and that 's true . and if this box a is just sitting here , not accelerating , these two forces are going to be equal and opposite . so it 's even more tempting to say that these two forces are equal and opposite because of the third law , but that 's not true . these two forces are equal and opposite because of the second law . the second law says if there 's no acceleration , then the net force has to be zero , the forces have to cancel . and that 's what 's happening here . these forces are equal and opposite , they 're canceling on box a . which is a way to know that they are not third law partner forces , cause third law partner forces are always exerted on different objects . they can never cancel if they 're third law partner forces . so what 's going on over here ? we 've got two forces that are canceling , that are equal and opposite , but they 're not third law partner forces , they 're partner forces are somewhere else . i have n't drawn their partner forces yet . so let 's try to figure out what they 're partner forces are . so let 's get rid of this , let 's come back to here , let 's slow it down to figure out what the partner force is , name the two objects interacting . so this force of gravity , i should n't be vague , i should call it the force on object a , our box a exerted by , well you ca n't just say gravity . gravity is not an object . so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is . the partner force can be found just by reversing these labels . so instead of the force on a by the earth , there 's got ta be an equal and opposite force , which is the force on the earth , by box a . so opposite means it has to point up . so it has to be an upward force . and that upward force has to be exerted on the earth , by box a , and this is kind of weird , because you may not have realized it , but if the earth is pulling down on a box , or you , that means you are pulling up on the earth . and this might seem ridiculous , i mean if you jump up , you jump up , you fall back down , you move around , but the earth just sits there . if your forces are equal , how come the earth does n't move around like you do . and again , it 's because just because the forces are the same , the acceleration does n't have to be the same . the mass of the earth is so big , compared to your mass , there 's basically no acceleration . even though the forces on you and the forces on the earth are the same . so these two are third law partner forces . these two are joined together forever . they have to be equal , no matter what happens , these two forces will always be equal . i do n't care if this box is accelerating or not accelerating , or that there 's motion or no motion . whether it 's hitting a wall , sitting on a table , falling through space , these two forces must always be equal and opposite , because of the third law . so how about this other force , this force that the table was exerting . so this is , the force on a by the table . so if i wan na label it correctly , i 'd call it the force on box a , exerted by the table . now finding the third law partner force is easy , i can just reverse these labels , and i 'd get that there must be , instead of an upwards force , a downwards force on the table , by a . so i 'm gon na have another force here on the table . it 's gon na be a downward force . downward force on the table by a , that 's the third law partner force to this upward force that the table is exerting . these two forces are also third law partner forces . these forces are going to be equal and opposite no matter what happens . this force on box a by the table . and this force on the table by box a must be equal no matter what happens , but the force on box a by the table , does not have to be equal and opposite to the force on a by the earth . it happens to be equal and opposite , in a case where there 's no acceleration . if we stuck this whole situation into an elevator , or a rocket that had some huge acceleration upwards , even if there 's acceleration upwards , these partner forces have to be equal . so the force on a by the table , and the force on the table by a will have to be equal . similarly the force on the earth by a , and the force on a by the earth have to be equal . but no longer will these two forces have to be equal , cause they 're not partner forces . they might be equal and opposite in some circumstances , but they do n't always have to be equal and opposite . if we 're accelerating upwards , this upward force on the box , must be bigger than the downwards force on the box . so these wo n't be equal . recapping quickly , newtons 's third law is a statement about the forces on two different objects . and because it 's about two different objects , those forces can never cancel . to find the newtons 's third law partner force , just reverse the label after you 've identified the two objects that are interacting . the third law partner forces have to be equal in magnitude , even if one object is larger than the other , or has more charge or any property that might seem like it would convey more force , than another object . if those are the two objects interacting , their forces must be of equal magnitude and opposite directions , the forces instantaneously generated this partner forces . and be careful , some forces might seem like partner forces , and might be equal and opposite , but they 're not necessarily third law partner forces . they made just be equal and opposite for other reasons .
|
so it has to be an upward force . and that upward force has to be exerted on the earth , by box a , and this is kind of weird , because you may not have realized it , but if the earth is pulling down on a box , or you , that means you are pulling up on the earth . and this might seem ridiculous , i mean if you jump up , you jump up , you fall back down , you move around , but the earth just sits there .
|
does it mean that the box is pulling the earth with somekind of gravitationnal field ?
|
we should talk a little more about newtons 's third law , because there are some deep misconceptions that many people have about this law . it seems simple , but it 's not nearly as simple as you might think . so people often phrase it as , for every action there 's an equal and opposite reaction . but that 's just way too vague to be useful . so a version that 's a little better , says that for every force , there 's an equal and opposite force . so this is a little better . the equal sign means that these forces are equal in magnitude . and this negative sign means they 're just different by the direction of the vector . so these are vectors , so this says that this pink vector f , has the opposite direction , but equal in magnitude to this green vector f. but to show you why this is still a little bit too vague , consider this , if this is all you knew about newtons 's third law , that for every force , there 's an equal and opposite force , you might wonder , if you were clever , you might be like , wait a minute , if for every force f , right , there 's got to be a force that 's equal and opposite . well why does n't that just mean that every force in the universe cancels ? should n't every force just cancel then , at that point ? does n't that just mean that there 's no acceleration that 's even possible ? because if i go and exert a force f on something , if there 's gon na be a force negative f , does n't that mean that no matter what force i put forward , it 's just gon na get cancelled ? and the answer no , and the reason it 's no is because these two forces are exerted on different objects . so you have to be careful . so the reason i say that this statement of newtons 's third law is still a little bit too vague , is because this is really on different objects . so if this is the force on object a , exerted by object b , then this force over here has to be the force on object b , exerted by object a . in other words , these forces down here are exerted on different objects . i 'm gon na move this over to this side . i 'm gon na move this over to here . let 's draw two different objects to show explicitly what i mean . so if there was some object a , so i put some object a in here . just wan na make sure there 's an object a . let 's say this is object a , and it had this green force exerted on it , f. so this object right here is a . well , there 's gon na be another object , object b . we 'll just make it another circle . so we 'll make it look like this . so here 's object b . and it 's gon na have this pink force , f , negative f exerted on it . so i 'm gon na call this object b . now we 're okay , now we know these forces ca n't cancel , and the reason these forces ca n't cancel , is cause they 're on two different objects . but when you just say that newtons 's third law , is that every force has an equal and opposite force , it 's not clear that it has to be on different objects . but it does have to be on different objects . so these newtons force law pairs , often times is called force pairs , or newton 's third law partner forces , are always on different objects . so the convention i 'm using is that the first letter represents the object that the force is on . so this a represents that this green force f this green force f , is on a and it 's exerted by b . and this shows that it 's exerted on b , because the first letter 's on the first one , and it 's exerted by the second object , a . so this pink force is exerted on b . this green force is exerted on a . they 're equal and opposite , they do not cancel , they can not cancel because they 're not on the same object . so that 's why these do n't cancel . and they are the same magnitude , even if the two objects are not the same size . this is another misconception , if object a is a planet , a big planet . or maybe a star , this is yellow , it looks like a star . let 's say this is some big star , and this is some smaller planet orbiting that star . this is not to scale , unless this planet was enormous . so this is some planet , but this planet could be hundreds , thousands of times , millions of times less massive than this star but it would still exert the same force . so if this star is pulling on the planet with this pink force negative f , then this planet has to be pulling on the star with this green force f and they have to have the same magnitude , even if they are different sizes . so people quote newtons 's third law , but sometimes they do n't really believe it . if i told you this planet was a million times less massive than this star , people would want to say that well , then the star obviously pulls more on the planet , than the planet pulls on the star . but that 's not true according to newtons 's third law . and newtons 's third law says that they have to be the same , even if they 're different sizes . so if this was the earth and this was the moon , the earth pulls on the moon , just as much as the moon pulls on the earth . and you might still object , you might say , wait that makes no sense , i know the star just basically sits there and the planet gets whipped around in a circle . how come this planet 's getting whipped around and the star 's just staying put ? that 's because , just because the forces are equal , that does n't mean that the result is equal . in other words , the forces could be equal , but the accelerations do n't have to be equal . acceleration is gon na be the net force divided by the mass . so even if the force is the same , you divide by that mass , you 'll get a different acceleration and that 's why the result of the force does not have to be the same , even though the forces do have to be the same , because of newtons 's third law . another misconception people sometimes make , is they think there might be a delay in the creation of this newtons 's third law partner force . and people think , maybe if i exert this first force fast enough , i can catch the universe sleeping , and there might be some sort of delay in the creation of this other force . but that 's not true , newtons 's third law is universal . no matter what the situation , no matter what the acceleration or non acceleration , or motion or no motion , whether one object is bigger or smaller , if their newtons 's third law partner forces , they are equal they are opposite and they are always equal and opposite , at every given moment in time . so even if i came in all guns a blazing , chuck norris style , trying to dropkick some wall . that does not look like the correct form for a drop kick . but even if i came in , flying at this wall , as soon as i start to make contact with the wall , i 'm gon na exert a force on the wall , and the wall has to exert a force back . so i 'd exert a force on the wall to the right . and this would be the force on the wall , by my foot . there 'd have to be an equal and opposite force instantly transmitted backwards , on my foot . so this would be the force on my foot , by the wall . this happens instantaneously , there is no delay . you ca n't kick this wall fast enough , for this other force to not be generated instantaneously . as soon as your foot starts to exert any force on the wall what so ever , the wall is gon na start exerting that same force back on your foot . so newtons 's third law is universal , but people still have trouble identifying these third law partner forces . so one of the best ways to do it , is by listing both objects , as soon as you list both objects , well to figure out where the partner force is , you can just reverse these labels . so i know over here , if one of my forces is the force on the wall by my foot , to find the partner force to this force , i can just reverse the labels and say it 's got ta be the force on my foot , by the wall , which i drew over here . so this is a great way to identify the third law partner forces , cause it 's not always obvious what force is the partner force . so to show you how this can be tricky , consider this example . say we got the ground and a table . so this example drives people crazy for some reason . if i 've got a box sitting on a table , we 'll call it box a . box a is gon na have forces exerted on it . one of those forces is gon na be the gravitational force . so the force of gravity is gon na pull straight down on box a , and if i were to ask you , what force is the third law partner force to this force of gravity , i 'm willing to bet a lot of people might say , well there 's an upwards force on box a , exerted by the table . and that 's true . and if this box a is just sitting here , not accelerating , these two forces are going to be equal and opposite . so it 's even more tempting to say that these two forces are equal and opposite because of the third law , but that 's not true . these two forces are equal and opposite because of the second law . the second law says if there 's no acceleration , then the net force has to be zero , the forces have to cancel . and that 's what 's happening here . these forces are equal and opposite , they 're canceling on box a . which is a way to know that they are not third law partner forces , cause third law partner forces are always exerted on different objects . they can never cancel if they 're third law partner forces . so what 's going on over here ? we 've got two forces that are canceling , that are equal and opposite , but they 're not third law partner forces , they 're partner forces are somewhere else . i have n't drawn their partner forces yet . so let 's try to figure out what they 're partner forces are . so let 's get rid of this , let 's come back to here , let 's slow it down to figure out what the partner force is , name the two objects interacting . so this force of gravity , i should n't be vague , i should call it the force on object a , our box a exerted by , well you ca n't just say gravity . gravity is not an object . so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is . the partner force can be found just by reversing these labels . so instead of the force on a by the earth , there 's got ta be an equal and opposite force , which is the force on the earth , by box a . so opposite means it has to point up . so it has to be an upward force . and that upward force has to be exerted on the earth , by box a , and this is kind of weird , because you may not have realized it , but if the earth is pulling down on a box , or you , that means you are pulling up on the earth . and this might seem ridiculous , i mean if you jump up , you jump up , you fall back down , you move around , but the earth just sits there . if your forces are equal , how come the earth does n't move around like you do . and again , it 's because just because the forces are the same , the acceleration does n't have to be the same . the mass of the earth is so big , compared to your mass , there 's basically no acceleration . even though the forces on you and the forces on the earth are the same . so these two are third law partner forces . these two are joined together forever . they have to be equal , no matter what happens , these two forces will always be equal . i do n't care if this box is accelerating or not accelerating , or that there 's motion or no motion . whether it 's hitting a wall , sitting on a table , falling through space , these two forces must always be equal and opposite , because of the third law . so how about this other force , this force that the table was exerting . so this is , the force on a by the table . so if i wan na label it correctly , i 'd call it the force on box a , exerted by the table . now finding the third law partner force is easy , i can just reverse these labels , and i 'd get that there must be , instead of an upwards force , a downwards force on the table , by a . so i 'm gon na have another force here on the table . it 's gon na be a downward force . downward force on the table by a , that 's the third law partner force to this upward force that the table is exerting . these two forces are also third law partner forces . these forces are going to be equal and opposite no matter what happens . this force on box a by the table . and this force on the table by box a must be equal no matter what happens , but the force on box a by the table , does not have to be equal and opposite to the force on a by the earth . it happens to be equal and opposite , in a case where there 's no acceleration . if we stuck this whole situation into an elevator , or a rocket that had some huge acceleration upwards , even if there 's acceleration upwards , these partner forces have to be equal . so the force on a by the table , and the force on the table by a will have to be equal . similarly the force on the earth by a , and the force on a by the earth have to be equal . but no longer will these two forces have to be equal , cause they 're not partner forces . they might be equal and opposite in some circumstances , but they do n't always have to be equal and opposite . if we 're accelerating upwards , this upward force on the box , must be bigger than the downwards force on the box . so these wo n't be equal . recapping quickly , newtons 's third law is a statement about the forces on two different objects . and because it 's about two different objects , those forces can never cancel . to find the newtons 's third law partner force , just reverse the label after you 've identified the two objects that are interacting . the third law partner forces have to be equal in magnitude , even if one object is larger than the other , or has more charge or any property that might seem like it would convey more force , than another object . if those are the two objects interacting , their forces must be of equal magnitude and opposite directions , the forces instantaneously generated this partner forces . and be careful , some forces might seem like partner forces , and might be equal and opposite , but they 're not necessarily third law partner forces . they made just be equal and opposite for other reasons .
|
so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is .
|
what 's the force opposing the force of friction ?
|
we should talk a little more about newtons 's third law , because there are some deep misconceptions that many people have about this law . it seems simple , but it 's not nearly as simple as you might think . so people often phrase it as , for every action there 's an equal and opposite reaction . but that 's just way too vague to be useful . so a version that 's a little better , says that for every force , there 's an equal and opposite force . so this is a little better . the equal sign means that these forces are equal in magnitude . and this negative sign means they 're just different by the direction of the vector . so these are vectors , so this says that this pink vector f , has the opposite direction , but equal in magnitude to this green vector f. but to show you why this is still a little bit too vague , consider this , if this is all you knew about newtons 's third law , that for every force , there 's an equal and opposite force , you might wonder , if you were clever , you might be like , wait a minute , if for every force f , right , there 's got to be a force that 's equal and opposite . well why does n't that just mean that every force in the universe cancels ? should n't every force just cancel then , at that point ? does n't that just mean that there 's no acceleration that 's even possible ? because if i go and exert a force f on something , if there 's gon na be a force negative f , does n't that mean that no matter what force i put forward , it 's just gon na get cancelled ? and the answer no , and the reason it 's no is because these two forces are exerted on different objects . so you have to be careful . so the reason i say that this statement of newtons 's third law is still a little bit too vague , is because this is really on different objects . so if this is the force on object a , exerted by object b , then this force over here has to be the force on object b , exerted by object a . in other words , these forces down here are exerted on different objects . i 'm gon na move this over to this side . i 'm gon na move this over to here . let 's draw two different objects to show explicitly what i mean . so if there was some object a , so i put some object a in here . just wan na make sure there 's an object a . let 's say this is object a , and it had this green force exerted on it , f. so this object right here is a . well , there 's gon na be another object , object b . we 'll just make it another circle . so we 'll make it look like this . so here 's object b . and it 's gon na have this pink force , f , negative f exerted on it . so i 'm gon na call this object b . now we 're okay , now we know these forces ca n't cancel , and the reason these forces ca n't cancel , is cause they 're on two different objects . but when you just say that newtons 's third law , is that every force has an equal and opposite force , it 's not clear that it has to be on different objects . but it does have to be on different objects . so these newtons force law pairs , often times is called force pairs , or newton 's third law partner forces , are always on different objects . so the convention i 'm using is that the first letter represents the object that the force is on . so this a represents that this green force f this green force f , is on a and it 's exerted by b . and this shows that it 's exerted on b , because the first letter 's on the first one , and it 's exerted by the second object , a . so this pink force is exerted on b . this green force is exerted on a . they 're equal and opposite , they do not cancel , they can not cancel because they 're not on the same object . so that 's why these do n't cancel . and they are the same magnitude , even if the two objects are not the same size . this is another misconception , if object a is a planet , a big planet . or maybe a star , this is yellow , it looks like a star . let 's say this is some big star , and this is some smaller planet orbiting that star . this is not to scale , unless this planet was enormous . so this is some planet , but this planet could be hundreds , thousands of times , millions of times less massive than this star but it would still exert the same force . so if this star is pulling on the planet with this pink force negative f , then this planet has to be pulling on the star with this green force f and they have to have the same magnitude , even if they are different sizes . so people quote newtons 's third law , but sometimes they do n't really believe it . if i told you this planet was a million times less massive than this star , people would want to say that well , then the star obviously pulls more on the planet , than the planet pulls on the star . but that 's not true according to newtons 's third law . and newtons 's third law says that they have to be the same , even if they 're different sizes . so if this was the earth and this was the moon , the earth pulls on the moon , just as much as the moon pulls on the earth . and you might still object , you might say , wait that makes no sense , i know the star just basically sits there and the planet gets whipped around in a circle . how come this planet 's getting whipped around and the star 's just staying put ? that 's because , just because the forces are equal , that does n't mean that the result is equal . in other words , the forces could be equal , but the accelerations do n't have to be equal . acceleration is gon na be the net force divided by the mass . so even if the force is the same , you divide by that mass , you 'll get a different acceleration and that 's why the result of the force does not have to be the same , even though the forces do have to be the same , because of newtons 's third law . another misconception people sometimes make , is they think there might be a delay in the creation of this newtons 's third law partner force . and people think , maybe if i exert this first force fast enough , i can catch the universe sleeping , and there might be some sort of delay in the creation of this other force . but that 's not true , newtons 's third law is universal . no matter what the situation , no matter what the acceleration or non acceleration , or motion or no motion , whether one object is bigger or smaller , if their newtons 's third law partner forces , they are equal they are opposite and they are always equal and opposite , at every given moment in time . so even if i came in all guns a blazing , chuck norris style , trying to dropkick some wall . that does not look like the correct form for a drop kick . but even if i came in , flying at this wall , as soon as i start to make contact with the wall , i 'm gon na exert a force on the wall , and the wall has to exert a force back . so i 'd exert a force on the wall to the right . and this would be the force on the wall , by my foot . there 'd have to be an equal and opposite force instantly transmitted backwards , on my foot . so this would be the force on my foot , by the wall . this happens instantaneously , there is no delay . you ca n't kick this wall fast enough , for this other force to not be generated instantaneously . as soon as your foot starts to exert any force on the wall what so ever , the wall is gon na start exerting that same force back on your foot . so newtons 's third law is universal , but people still have trouble identifying these third law partner forces . so one of the best ways to do it , is by listing both objects , as soon as you list both objects , well to figure out where the partner force is , you can just reverse these labels . so i know over here , if one of my forces is the force on the wall by my foot , to find the partner force to this force , i can just reverse the labels and say it 's got ta be the force on my foot , by the wall , which i drew over here . so this is a great way to identify the third law partner forces , cause it 's not always obvious what force is the partner force . so to show you how this can be tricky , consider this example . say we got the ground and a table . so this example drives people crazy for some reason . if i 've got a box sitting on a table , we 'll call it box a . box a is gon na have forces exerted on it . one of those forces is gon na be the gravitational force . so the force of gravity is gon na pull straight down on box a , and if i were to ask you , what force is the third law partner force to this force of gravity , i 'm willing to bet a lot of people might say , well there 's an upwards force on box a , exerted by the table . and that 's true . and if this box a is just sitting here , not accelerating , these two forces are going to be equal and opposite . so it 's even more tempting to say that these two forces are equal and opposite because of the third law , but that 's not true . these two forces are equal and opposite because of the second law . the second law says if there 's no acceleration , then the net force has to be zero , the forces have to cancel . and that 's what 's happening here . these forces are equal and opposite , they 're canceling on box a . which is a way to know that they are not third law partner forces , cause third law partner forces are always exerted on different objects . they can never cancel if they 're third law partner forces . so what 's going on over here ? we 've got two forces that are canceling , that are equal and opposite , but they 're not third law partner forces , they 're partner forces are somewhere else . i have n't drawn their partner forces yet . so let 's try to figure out what they 're partner forces are . so let 's get rid of this , let 's come back to here , let 's slow it down to figure out what the partner force is , name the two objects interacting . so this force of gravity , i should n't be vague , i should call it the force on object a , our box a exerted by , well you ca n't just say gravity . gravity is not an object . so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is . the partner force can be found just by reversing these labels . so instead of the force on a by the earth , there 's got ta be an equal and opposite force , which is the force on the earth , by box a . so opposite means it has to point up . so it has to be an upward force . and that upward force has to be exerted on the earth , by box a , and this is kind of weird , because you may not have realized it , but if the earth is pulling down on a box , or you , that means you are pulling up on the earth . and this might seem ridiculous , i mean if you jump up , you jump up , you fall back down , you move around , but the earth just sits there . if your forces are equal , how come the earth does n't move around like you do . and again , it 's because just because the forces are the same , the acceleration does n't have to be the same . the mass of the earth is so big , compared to your mass , there 's basically no acceleration . even though the forces on you and the forces on the earth are the same . so these two are third law partner forces . these two are joined together forever . they have to be equal , no matter what happens , these two forces will always be equal . i do n't care if this box is accelerating or not accelerating , or that there 's motion or no motion . whether it 's hitting a wall , sitting on a table , falling through space , these two forces must always be equal and opposite , because of the third law . so how about this other force , this force that the table was exerting . so this is , the force on a by the table . so if i wan na label it correctly , i 'd call it the force on box a , exerted by the table . now finding the third law partner force is easy , i can just reverse these labels , and i 'd get that there must be , instead of an upwards force , a downwards force on the table , by a . so i 'm gon na have another force here on the table . it 's gon na be a downward force . downward force on the table by a , that 's the third law partner force to this upward force that the table is exerting . these two forces are also third law partner forces . these forces are going to be equal and opposite no matter what happens . this force on box a by the table . and this force on the table by box a must be equal no matter what happens , but the force on box a by the table , does not have to be equal and opposite to the force on a by the earth . it happens to be equal and opposite , in a case where there 's no acceleration . if we stuck this whole situation into an elevator , or a rocket that had some huge acceleration upwards , even if there 's acceleration upwards , these partner forces have to be equal . so the force on a by the table , and the force on the table by a will have to be equal . similarly the force on the earth by a , and the force on a by the earth have to be equal . but no longer will these two forces have to be equal , cause they 're not partner forces . they might be equal and opposite in some circumstances , but they do n't always have to be equal and opposite . if we 're accelerating upwards , this upward force on the box , must be bigger than the downwards force on the box . so these wo n't be equal . recapping quickly , newtons 's third law is a statement about the forces on two different objects . and because it 's about two different objects , those forces can never cancel . to find the newtons 's third law partner force , just reverse the label after you 've identified the two objects that are interacting . the third law partner forces have to be equal in magnitude , even if one object is larger than the other , or has more charge or any property that might seem like it would convey more force , than another object . if those are the two objects interacting , their forces must be of equal magnitude and opposite directions , the forces instantaneously generated this partner forces . and be careful , some forces might seem like partner forces , and might be equal and opposite , but they 're not necessarily third law partner forces . they made just be equal and opposite for other reasons .
|
so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is .
|
so there 's no force that opposes friction ?
|
we should talk a little more about newtons 's third law , because there are some deep misconceptions that many people have about this law . it seems simple , but it 's not nearly as simple as you might think . so people often phrase it as , for every action there 's an equal and opposite reaction . but that 's just way too vague to be useful . so a version that 's a little better , says that for every force , there 's an equal and opposite force . so this is a little better . the equal sign means that these forces are equal in magnitude . and this negative sign means they 're just different by the direction of the vector . so these are vectors , so this says that this pink vector f , has the opposite direction , but equal in magnitude to this green vector f. but to show you why this is still a little bit too vague , consider this , if this is all you knew about newtons 's third law , that for every force , there 's an equal and opposite force , you might wonder , if you were clever , you might be like , wait a minute , if for every force f , right , there 's got to be a force that 's equal and opposite . well why does n't that just mean that every force in the universe cancels ? should n't every force just cancel then , at that point ? does n't that just mean that there 's no acceleration that 's even possible ? because if i go and exert a force f on something , if there 's gon na be a force negative f , does n't that mean that no matter what force i put forward , it 's just gon na get cancelled ? and the answer no , and the reason it 's no is because these two forces are exerted on different objects . so you have to be careful . so the reason i say that this statement of newtons 's third law is still a little bit too vague , is because this is really on different objects . so if this is the force on object a , exerted by object b , then this force over here has to be the force on object b , exerted by object a . in other words , these forces down here are exerted on different objects . i 'm gon na move this over to this side . i 'm gon na move this over to here . let 's draw two different objects to show explicitly what i mean . so if there was some object a , so i put some object a in here . just wan na make sure there 's an object a . let 's say this is object a , and it had this green force exerted on it , f. so this object right here is a . well , there 's gon na be another object , object b . we 'll just make it another circle . so we 'll make it look like this . so here 's object b . and it 's gon na have this pink force , f , negative f exerted on it . so i 'm gon na call this object b . now we 're okay , now we know these forces ca n't cancel , and the reason these forces ca n't cancel , is cause they 're on two different objects . but when you just say that newtons 's third law , is that every force has an equal and opposite force , it 's not clear that it has to be on different objects . but it does have to be on different objects . so these newtons force law pairs , often times is called force pairs , or newton 's third law partner forces , are always on different objects . so the convention i 'm using is that the first letter represents the object that the force is on . so this a represents that this green force f this green force f , is on a and it 's exerted by b . and this shows that it 's exerted on b , because the first letter 's on the first one , and it 's exerted by the second object , a . so this pink force is exerted on b . this green force is exerted on a . they 're equal and opposite , they do not cancel , they can not cancel because they 're not on the same object . so that 's why these do n't cancel . and they are the same magnitude , even if the two objects are not the same size . this is another misconception , if object a is a planet , a big planet . or maybe a star , this is yellow , it looks like a star . let 's say this is some big star , and this is some smaller planet orbiting that star . this is not to scale , unless this planet was enormous . so this is some planet , but this planet could be hundreds , thousands of times , millions of times less massive than this star but it would still exert the same force . so if this star is pulling on the planet with this pink force negative f , then this planet has to be pulling on the star with this green force f and they have to have the same magnitude , even if they are different sizes . so people quote newtons 's third law , but sometimes they do n't really believe it . if i told you this planet was a million times less massive than this star , people would want to say that well , then the star obviously pulls more on the planet , than the planet pulls on the star . but that 's not true according to newtons 's third law . and newtons 's third law says that they have to be the same , even if they 're different sizes . so if this was the earth and this was the moon , the earth pulls on the moon , just as much as the moon pulls on the earth . and you might still object , you might say , wait that makes no sense , i know the star just basically sits there and the planet gets whipped around in a circle . how come this planet 's getting whipped around and the star 's just staying put ? that 's because , just because the forces are equal , that does n't mean that the result is equal . in other words , the forces could be equal , but the accelerations do n't have to be equal . acceleration is gon na be the net force divided by the mass . so even if the force is the same , you divide by that mass , you 'll get a different acceleration and that 's why the result of the force does not have to be the same , even though the forces do have to be the same , because of newtons 's third law . another misconception people sometimes make , is they think there might be a delay in the creation of this newtons 's third law partner force . and people think , maybe if i exert this first force fast enough , i can catch the universe sleeping , and there might be some sort of delay in the creation of this other force . but that 's not true , newtons 's third law is universal . no matter what the situation , no matter what the acceleration or non acceleration , or motion or no motion , whether one object is bigger or smaller , if their newtons 's third law partner forces , they are equal they are opposite and they are always equal and opposite , at every given moment in time . so even if i came in all guns a blazing , chuck norris style , trying to dropkick some wall . that does not look like the correct form for a drop kick . but even if i came in , flying at this wall , as soon as i start to make contact with the wall , i 'm gon na exert a force on the wall , and the wall has to exert a force back . so i 'd exert a force on the wall to the right . and this would be the force on the wall , by my foot . there 'd have to be an equal and opposite force instantly transmitted backwards , on my foot . so this would be the force on my foot , by the wall . this happens instantaneously , there is no delay . you ca n't kick this wall fast enough , for this other force to not be generated instantaneously . as soon as your foot starts to exert any force on the wall what so ever , the wall is gon na start exerting that same force back on your foot . so newtons 's third law is universal , but people still have trouble identifying these third law partner forces . so one of the best ways to do it , is by listing both objects , as soon as you list both objects , well to figure out where the partner force is , you can just reverse these labels . so i know over here , if one of my forces is the force on the wall by my foot , to find the partner force to this force , i can just reverse the labels and say it 's got ta be the force on my foot , by the wall , which i drew over here . so this is a great way to identify the third law partner forces , cause it 's not always obvious what force is the partner force . so to show you how this can be tricky , consider this example . say we got the ground and a table . so this example drives people crazy for some reason . if i 've got a box sitting on a table , we 'll call it box a . box a is gon na have forces exerted on it . one of those forces is gon na be the gravitational force . so the force of gravity is gon na pull straight down on box a , and if i were to ask you , what force is the third law partner force to this force of gravity , i 'm willing to bet a lot of people might say , well there 's an upwards force on box a , exerted by the table . and that 's true . and if this box a is just sitting here , not accelerating , these two forces are going to be equal and opposite . so it 's even more tempting to say that these two forces are equal and opposite because of the third law , but that 's not true . these two forces are equal and opposite because of the second law . the second law says if there 's no acceleration , then the net force has to be zero , the forces have to cancel . and that 's what 's happening here . these forces are equal and opposite , they 're canceling on box a . which is a way to know that they are not third law partner forces , cause third law partner forces are always exerted on different objects . they can never cancel if they 're third law partner forces . so what 's going on over here ? we 've got two forces that are canceling , that are equal and opposite , but they 're not third law partner forces , they 're partner forces are somewhere else . i have n't drawn their partner forces yet . so let 's try to figure out what they 're partner forces are . so let 's get rid of this , let 's come back to here , let 's slow it down to figure out what the partner force is , name the two objects interacting . so this force of gravity , i should n't be vague , i should call it the force on object a , our box a exerted by , well you ca n't just say gravity . gravity is not an object . so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is . the partner force can be found just by reversing these labels . so instead of the force on a by the earth , there 's got ta be an equal and opposite force , which is the force on the earth , by box a . so opposite means it has to point up . so it has to be an upward force . and that upward force has to be exerted on the earth , by box a , and this is kind of weird , because you may not have realized it , but if the earth is pulling down on a box , or you , that means you are pulling up on the earth . and this might seem ridiculous , i mean if you jump up , you jump up , you fall back down , you move around , but the earth just sits there . if your forces are equal , how come the earth does n't move around like you do . and again , it 's because just because the forces are the same , the acceleration does n't have to be the same . the mass of the earth is so big , compared to your mass , there 's basically no acceleration . even though the forces on you and the forces on the earth are the same . so these two are third law partner forces . these two are joined together forever . they have to be equal , no matter what happens , these two forces will always be equal . i do n't care if this box is accelerating or not accelerating , or that there 's motion or no motion . whether it 's hitting a wall , sitting on a table , falling through space , these two forces must always be equal and opposite , because of the third law . so how about this other force , this force that the table was exerting . so this is , the force on a by the table . so if i wan na label it correctly , i 'd call it the force on box a , exerted by the table . now finding the third law partner force is easy , i can just reverse these labels , and i 'd get that there must be , instead of an upwards force , a downwards force on the table , by a . so i 'm gon na have another force here on the table . it 's gon na be a downward force . downward force on the table by a , that 's the third law partner force to this upward force that the table is exerting . these two forces are also third law partner forces . these forces are going to be equal and opposite no matter what happens . this force on box a by the table . and this force on the table by box a must be equal no matter what happens , but the force on box a by the table , does not have to be equal and opposite to the force on a by the earth . it happens to be equal and opposite , in a case where there 's no acceleration . if we stuck this whole situation into an elevator , or a rocket that had some huge acceleration upwards , even if there 's acceleration upwards , these partner forces have to be equal . so the force on a by the table , and the force on the table by a will have to be equal . similarly the force on the earth by a , and the force on a by the earth have to be equal . but no longer will these two forces have to be equal , cause they 're not partner forces . they might be equal and opposite in some circumstances , but they do n't always have to be equal and opposite . if we 're accelerating upwards , this upward force on the box , must be bigger than the downwards force on the box . so these wo n't be equal . recapping quickly , newtons 's third law is a statement about the forces on two different objects . and because it 's about two different objects , those forces can never cancel . to find the newtons 's third law partner force , just reverse the label after you 've identified the two objects that are interacting . the third law partner forces have to be equal in magnitude , even if one object is larger than the other , or has more charge or any property that might seem like it would convey more force , than another object . if those are the two objects interacting , their forces must be of equal magnitude and opposite directions , the forces instantaneously generated this partner forces . and be careful , some forces might seem like partner forces , and might be equal and opposite , but they 're not necessarily third law partner forces . they made just be equal and opposite for other reasons .
|
in other words , the forces could be equal , but the accelerations do n't have to be equal . acceleration is gon na be the net force divided by the mass . so even if the force is the same , you divide by that mass , you 'll get a different acceleration and that 's why the result of the force does not have to be the same , even though the forces do have to be the same , because of newtons 's third law .
|
also , is there a presence of a net force hence the upward acceleration ?
|
we should talk a little more about newtons 's third law , because there are some deep misconceptions that many people have about this law . it seems simple , but it 's not nearly as simple as you might think . so people often phrase it as , for every action there 's an equal and opposite reaction . but that 's just way too vague to be useful . so a version that 's a little better , says that for every force , there 's an equal and opposite force . so this is a little better . the equal sign means that these forces are equal in magnitude . and this negative sign means they 're just different by the direction of the vector . so these are vectors , so this says that this pink vector f , has the opposite direction , but equal in magnitude to this green vector f. but to show you why this is still a little bit too vague , consider this , if this is all you knew about newtons 's third law , that for every force , there 's an equal and opposite force , you might wonder , if you were clever , you might be like , wait a minute , if for every force f , right , there 's got to be a force that 's equal and opposite . well why does n't that just mean that every force in the universe cancels ? should n't every force just cancel then , at that point ? does n't that just mean that there 's no acceleration that 's even possible ? because if i go and exert a force f on something , if there 's gon na be a force negative f , does n't that mean that no matter what force i put forward , it 's just gon na get cancelled ? and the answer no , and the reason it 's no is because these two forces are exerted on different objects . so you have to be careful . so the reason i say that this statement of newtons 's third law is still a little bit too vague , is because this is really on different objects . so if this is the force on object a , exerted by object b , then this force over here has to be the force on object b , exerted by object a . in other words , these forces down here are exerted on different objects . i 'm gon na move this over to this side . i 'm gon na move this over to here . let 's draw two different objects to show explicitly what i mean . so if there was some object a , so i put some object a in here . just wan na make sure there 's an object a . let 's say this is object a , and it had this green force exerted on it , f. so this object right here is a . well , there 's gon na be another object , object b . we 'll just make it another circle . so we 'll make it look like this . so here 's object b . and it 's gon na have this pink force , f , negative f exerted on it . so i 'm gon na call this object b . now we 're okay , now we know these forces ca n't cancel , and the reason these forces ca n't cancel , is cause they 're on two different objects . but when you just say that newtons 's third law , is that every force has an equal and opposite force , it 's not clear that it has to be on different objects . but it does have to be on different objects . so these newtons force law pairs , often times is called force pairs , or newton 's third law partner forces , are always on different objects . so the convention i 'm using is that the first letter represents the object that the force is on . so this a represents that this green force f this green force f , is on a and it 's exerted by b . and this shows that it 's exerted on b , because the first letter 's on the first one , and it 's exerted by the second object , a . so this pink force is exerted on b . this green force is exerted on a . they 're equal and opposite , they do not cancel , they can not cancel because they 're not on the same object . so that 's why these do n't cancel . and they are the same magnitude , even if the two objects are not the same size . this is another misconception , if object a is a planet , a big planet . or maybe a star , this is yellow , it looks like a star . let 's say this is some big star , and this is some smaller planet orbiting that star . this is not to scale , unless this planet was enormous . so this is some planet , but this planet could be hundreds , thousands of times , millions of times less massive than this star but it would still exert the same force . so if this star is pulling on the planet with this pink force negative f , then this planet has to be pulling on the star with this green force f and they have to have the same magnitude , even if they are different sizes . so people quote newtons 's third law , but sometimes they do n't really believe it . if i told you this planet was a million times less massive than this star , people would want to say that well , then the star obviously pulls more on the planet , than the planet pulls on the star . but that 's not true according to newtons 's third law . and newtons 's third law says that they have to be the same , even if they 're different sizes . so if this was the earth and this was the moon , the earth pulls on the moon , just as much as the moon pulls on the earth . and you might still object , you might say , wait that makes no sense , i know the star just basically sits there and the planet gets whipped around in a circle . how come this planet 's getting whipped around and the star 's just staying put ? that 's because , just because the forces are equal , that does n't mean that the result is equal . in other words , the forces could be equal , but the accelerations do n't have to be equal . acceleration is gon na be the net force divided by the mass . so even if the force is the same , you divide by that mass , you 'll get a different acceleration and that 's why the result of the force does not have to be the same , even though the forces do have to be the same , because of newtons 's third law . another misconception people sometimes make , is they think there might be a delay in the creation of this newtons 's third law partner force . and people think , maybe if i exert this first force fast enough , i can catch the universe sleeping , and there might be some sort of delay in the creation of this other force . but that 's not true , newtons 's third law is universal . no matter what the situation , no matter what the acceleration or non acceleration , or motion or no motion , whether one object is bigger or smaller , if their newtons 's third law partner forces , they are equal they are opposite and they are always equal and opposite , at every given moment in time . so even if i came in all guns a blazing , chuck norris style , trying to dropkick some wall . that does not look like the correct form for a drop kick . but even if i came in , flying at this wall , as soon as i start to make contact with the wall , i 'm gon na exert a force on the wall , and the wall has to exert a force back . so i 'd exert a force on the wall to the right . and this would be the force on the wall , by my foot . there 'd have to be an equal and opposite force instantly transmitted backwards , on my foot . so this would be the force on my foot , by the wall . this happens instantaneously , there is no delay . you ca n't kick this wall fast enough , for this other force to not be generated instantaneously . as soon as your foot starts to exert any force on the wall what so ever , the wall is gon na start exerting that same force back on your foot . so newtons 's third law is universal , but people still have trouble identifying these third law partner forces . so one of the best ways to do it , is by listing both objects , as soon as you list both objects , well to figure out where the partner force is , you can just reverse these labels . so i know over here , if one of my forces is the force on the wall by my foot , to find the partner force to this force , i can just reverse the labels and say it 's got ta be the force on my foot , by the wall , which i drew over here . so this is a great way to identify the third law partner forces , cause it 's not always obvious what force is the partner force . so to show you how this can be tricky , consider this example . say we got the ground and a table . so this example drives people crazy for some reason . if i 've got a box sitting on a table , we 'll call it box a . box a is gon na have forces exerted on it . one of those forces is gon na be the gravitational force . so the force of gravity is gon na pull straight down on box a , and if i were to ask you , what force is the third law partner force to this force of gravity , i 'm willing to bet a lot of people might say , well there 's an upwards force on box a , exerted by the table . and that 's true . and if this box a is just sitting here , not accelerating , these two forces are going to be equal and opposite . so it 's even more tempting to say that these two forces are equal and opposite because of the third law , but that 's not true . these two forces are equal and opposite because of the second law . the second law says if there 's no acceleration , then the net force has to be zero , the forces have to cancel . and that 's what 's happening here . these forces are equal and opposite , they 're canceling on box a . which is a way to know that they are not third law partner forces , cause third law partner forces are always exerted on different objects . they can never cancel if they 're third law partner forces . so what 's going on over here ? we 've got two forces that are canceling , that are equal and opposite , but they 're not third law partner forces , they 're partner forces are somewhere else . i have n't drawn their partner forces yet . so let 's try to figure out what they 're partner forces are . so let 's get rid of this , let 's come back to here , let 's slow it down to figure out what the partner force is , name the two objects interacting . so this force of gravity , i should n't be vague , i should call it the force on object a , our box a exerted by , well you ca n't just say gravity . gravity is not an object . so the object that is exerting this gravitational force on a , is the earth . so this force really , this gravitational force , if i wan na be careful , is the force on object a exerted by the earth . now it 's easy to figure out where the partner force is . the partner force can be found just by reversing these labels . so instead of the force on a by the earth , there 's got ta be an equal and opposite force , which is the force on the earth , by box a . so opposite means it has to point up . so it has to be an upward force . and that upward force has to be exerted on the earth , by box a , and this is kind of weird , because you may not have realized it , but if the earth is pulling down on a box , or you , that means you are pulling up on the earth . and this might seem ridiculous , i mean if you jump up , you jump up , you fall back down , you move around , but the earth just sits there . if your forces are equal , how come the earth does n't move around like you do . and again , it 's because just because the forces are the same , the acceleration does n't have to be the same . the mass of the earth is so big , compared to your mass , there 's basically no acceleration . even though the forces on you and the forces on the earth are the same . so these two are third law partner forces . these two are joined together forever . they have to be equal , no matter what happens , these two forces will always be equal . i do n't care if this box is accelerating or not accelerating , or that there 's motion or no motion . whether it 's hitting a wall , sitting on a table , falling through space , these two forces must always be equal and opposite , because of the third law . so how about this other force , this force that the table was exerting . so this is , the force on a by the table . so if i wan na label it correctly , i 'd call it the force on box a , exerted by the table . now finding the third law partner force is easy , i can just reverse these labels , and i 'd get that there must be , instead of an upwards force , a downwards force on the table , by a . so i 'm gon na have another force here on the table . it 's gon na be a downward force . downward force on the table by a , that 's the third law partner force to this upward force that the table is exerting . these two forces are also third law partner forces . these forces are going to be equal and opposite no matter what happens . this force on box a by the table . and this force on the table by box a must be equal no matter what happens , but the force on box a by the table , does not have to be equal and opposite to the force on a by the earth . it happens to be equal and opposite , in a case where there 's no acceleration . if we stuck this whole situation into an elevator , or a rocket that had some huge acceleration upwards , even if there 's acceleration upwards , these partner forces have to be equal . so the force on a by the table , and the force on the table by a will have to be equal . similarly the force on the earth by a , and the force on a by the earth have to be equal . but no longer will these two forces have to be equal , cause they 're not partner forces . they might be equal and opposite in some circumstances , but they do n't always have to be equal and opposite . if we 're accelerating upwards , this upward force on the box , must be bigger than the downwards force on the box . so these wo n't be equal . recapping quickly , newtons 's third law is a statement about the forces on two different objects . and because it 's about two different objects , those forces can never cancel . to find the newtons 's third law partner force , just reverse the label after you 've identified the two objects that are interacting . the third law partner forces have to be equal in magnitude , even if one object is larger than the other , or has more charge or any property that might seem like it would convey more force , than another object . if those are the two objects interacting , their forces must be of equal magnitude and opposite directions , the forces instantaneously generated this partner forces . and be careful , some forces might seem like partner forces , and might be equal and opposite , but they 're not necessarily third law partner forces . they made just be equal and opposite for other reasons .
|
as soon as your foot starts to exert any force on the wall what so ever , the wall is gon na start exerting that same force back on your foot . so newtons 's third law is universal , but people still have trouble identifying these third law partner forces . so one of the best ways to do it , is by listing both objects , as soon as you list both objects , well to figure out where the partner force is , you can just reverse these labels .
|
does the law apply in non inertial frames ?
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.