source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-1901 | optics, everyday-life, polarization, vision
Title: Why do sun glasses shield more sunlight from a specific angle? I started recently wearing sunglasses during my online classes as laptop screens started taking a toll on my poor eyesight (of course my physics teacher wanted it removed but that's beside the point).
I noticed on one occasion when I stretched my neck nearly 45 degrees towards my left, the screen went completely dark and I couldn't see a thing on my laptop. I thought that the battery must have died and so as I reached for my charger I saw the screen reappear. I also observed the same happening when I looked at the screen from the corner of my eye as I faced the left side of the laptop (from my peripheral vision). In the image the laptop would come towards the my right side, around 10-20 degrees.
The following is multiple choice question (with options) to answer.
Safety glasses should be worn around | [
"water",
"bleach",
"air",
"computers"
] | B | chemical splashing can cause harm to the eyes |
OpenBookQA | OpenBookQA-1902 | geophysics, sedimentology
Title: Does dirt compact itself over time? If so, how does this happen? If I were to bury something 10 feet (~3 metres) underground, with loose soil on top, would the ground naturally compact itself over time, until whatever I had buried has dirt tightly pressing against it on all sides?
What if I buried it 50 feet (~15 metres) underground?
If it exists, what is this compaction process called and how does it happen? Soil is a collection of various sized minerals grains, of various types of minerals produced by the weathering of rock. Typical soil minerals are clays, silts and sands.
The properties and behavior of different soil types depends of the composition of the soil: the proportion of clays, silts and sand in a soil. Sandy soils are well draining and clayey soils are sticky.
Between the grains of minerals that comprise a soil are spaces, called pores or pore spaces. The pores can be filled with either water or air, depending the location of water tables and wetting events like rain, snow melts or other forms of water inundation.
The density of a soil is dependent on the degree of compaction of the soil. For to a soil to be compacted, a stress has to be applied to the soil to realign the grains of soil which reduces the total volume of the pores and reduces the amount of air within the pores.
Consolidation of a soil occurs when pore space is reduced and water in a soil is displaced due to an applied stress.
Regarding having something buried and soil compacting around it over time, yes that will occur but it is a question of how much stress the soil experiences, the duration of time and the nature of the soil - sandy or clayey. Something buried for a day without any stresses not much will happen. But, something buried for thousands of years with people and animals walking over it, rain falling on the soil, vibrations from nearby human activity and an occasional earthquake all add to the stresses the soil will experience and increases the degree of compaction or consolidation over time.
The following is multiple choice question (with options) to answer.
Soil is produced naturally when, over a period of many years | [
"stones are rock solid",
"stones are blown up",
"stones are vaporized by storms",
"stones are worn down"
] | D | soil is formed by weathering |
OpenBookQA | OpenBookQA-1903 | algorithms, optimization, reference-request, approximation
What is the name of the problem?
How well can one hope to approximate the problem (assuming $\mathcal{P} \neq \mathcal{NP}$)?
I'm quite happy with the name and/or reference(s) to the problem. Maybe the answer to the second point follows easily or I can find out that myself. Among others, this problem can be seen as an instance of the Traveling Purchaser Problem. $\text{TPP}$ is a generalization of $\text{TSP}$ and was first proposed by T. Ramesh, Traveling purchaser problem, 1981. The problem is as follows:
We are given a set $M = \{ 1, ..., m \}$ of markets and a set of $N = \{ 1, ..., n \}$ of products. Also we are given $c_{ij}$, the cost of traveling from city $i$ to city $j$, and non-negative $d_{ij}$, the cost of a product $i$ at market $j$. The purchaser starts from his home city (for example city $1$), and travels to a subset of the $m$ cities and purchases each of the $n$ products in of the cities he visits, and return back to his home city. The objective is to find a tour for the purchaser that such that the sum of the travel and purchase costs are minimized.
The following is multiple choice question (with options) to answer.
A consumer must locate it's own | [
"tools",
"nutrition",
"soul",
"clothes"
] | B | a consumer can not produce its own food |
OpenBookQA | OpenBookQA-1904 | meteorology, geophysics, tropical-cyclone
Title: What is the largest hurricane possible? With Earth getting hotter and hurricanes also getting larger I wonder; Is there a limit on how big a hurricane can physically get? I am going to take an educated guess here because it is not possible(AFAIK) to accurately predict with any known skill what several decades into the future would be like.
Given that premise the largest hurricane in the future could be the size of the tropical extent of the Pacific Ocean or the Atlantic Ocean(wherever that begins and ends). Here I am only considering the Northern(or Southern) tropical extent of the Pacific or Atlantic Ocean because as we know a tropical cyclone cannot cross the equator as explained in this in depth answer Impossible or improbable? Hurricane crossing the equator. The thought process behind this idea is that hurricanes(tropical cyclones) dissipate on coming contact with land. Hence the maximum area of the largest cyclone in the future would have to be the ocean body maximum tropical extent(typically sea surface temperature (SST) greater than 27 degrees centigrade). Just in case if people are wondering why just the tropical extent and why not more than that ? It is because once you enter into mid latitude regions frontal processes could kick in(cold core cyclones-as an example -Can a tropical cyclone form in mid latitude oceanic waters?)
So if the tropical extent of the biggest oceans increases in the future one can imagine a very large possibly synoptic scale tropical cyclone.
Here I am excluding the North Indian Ocean basin because it does not have the surface area to compete with the North Pacific or North Atlantic
Secondly from this popular science article -How strong can a Hurricane get? and this one Are Category 6 Hurricanes coming soon ?
By the end of the 21st century, human-caused global warming will likely increase hurricane intensity, on average, by 2 to 11 percent, according to a review by NOAA's Geophysical Fluid Dynamics Laboratory, revised on Aug. 30, 2017.
followed by
The following is multiple choice question (with options) to answer.
the strength of a hurricane will increase when | [
"it hits the arctic circle",
"it meets a tornado",
"it from South Africa to Mexico",
"it travels around Antarctica"
] | C | as heat and moisture increases , the strength of a hurricane will increase |
OpenBookQA | OpenBookQA-1905 | ocean, oceanography, wind, waves, ocean-currents
Taking 10 meters (one of the smallest values in mid-latitudes) for the surface and bottom boundary layer thicknesses, that implies that in water depths shallower than 20 m the two boundary layers overlap. In water depths shallower than that, the transport in the surface layer is no longer perpendicular to the wind direction. The momentum input into the water by the wind (wind stress) is affected by the presence of the bottom and it is directly dissipated by bottom friction. The mixing by the wind (and wave breaking near the surf zone) results in additional mixing through the water column and facilitating well-mixed water columns. Under these conditions the wind-induced currents extend all the way to the bottom with the direction of the flow being a function of bottom depth, wind direction, and bottom slope. The presence of wind-induced currents does not preclude the occurrence of flow in the opposite direction of the wind.
A fantastic article summarizing the different flow conditions under different wind and wave fields in shallow water depths is given in Lentz and Fewings (2012). (Reprint)
Additional factors to consider are:
The following is multiple choice question (with options) to answer.
A sandbar is in the shallow portion of water where | [
"water is bloody",
"water is harder",
"water is falling",
"water adjusts things"
] | D | a sandbar is formed by water moving sediment downstream |
OpenBookQA | OpenBookQA-1906 | newtonian-mechanics, forces, kinematics, friction
Title: Why Do Objects move? Let's imagine a block resting on horizontal table. When We apply a force which is greater than frictional force it moves.
But why does this happen? Why can't friction withstand any force? As we know that one cause of friction is due to interlocking of irregularities, I think there is a opposing force as irregularities apply a normal force .
So why if applied force is increased the normal force can't withstand the increased force? Also is there any possibility that in a situation the frictional force could always cancel the applied force? Your image shows what is going on at the microscopic level between two surfaces. To understand why friction works, you have to look smaller, at the atomic level: and when you get to that point you're no longer taking about "friction" as we know it, but about physiochemical interactions between atoms and molecules. Those interactions are mediated by electromagnetic force and tend to be quite weak at the boundaries between two solid objects. As one example demonstrating the fundamentally chemical nature of the interactions, note that the reason it's easier to grip paper if your fingers are slightly damp is because the polar water molecules form bonds between your skin, the paper and each other, somewhat "gluing" everything together.
The following is multiple choice question (with options) to answer.
What can cause objects to repel each other? | [
"fake magnets",
"smell",
"identical charges",
"sunlight"
] | C | magnetism can cause objects to repel each other |
OpenBookQA | OpenBookQA-1907 | organic-chemistry
References (in the order of mentioned points)
A. Demirbas, "Biodiesel from Vegetable Oils with MgO Catalytic Transesterification in Supercritical Methanol" Pages 1645-1651, 22 Jul 2008 DOI: https://doi.org/10.1080/15567030701268401
Gizelle I. Almerindoa, Luiz F., D.Probsta Carlos E. ,M. Campos Rusiene , M.de Almeidac , Simoni M. P.Meneghettic, Mario R.Meneghettic , Jean-Marc Clacens, Humberto V.Fajardoe "Magnesium oxide prepared via metal–chitosan complexation method: Application as catalyst for transesterification of soybean oil and catalyst deactivation studies" Journal of Power Sources Volume 196, Issue 19, 1 October 2011, Pages 8057-8063 DOI: https://doi.org/10.1016/j.jpowsour.2011.05.030
http://www.asianjournalofchemistry.co.in/User/ViewFreeArticle.aspx?ArticleID=28_2_6
Jacek Skarżewski "Carbon-acylations in the presence of magnesium oxide. A simple synthesis of methanetricarboxylic esters"Tetrahedron Volume 45, Issue 14, 1989, Pages 4593-4598 DOI: https://doi.org/10.1016/S0040-4020(01)89094-3
The following is multiple choice question (with options) to answer.
An example of biofuel could be | [
"metal",
"the sun",
"leaves",
"the wind"
] | C | biofuel is used to produce electricity by burning |
OpenBookQA | OpenBookQA-1908 | resonance, vibrations, coupled-oscillators
Title: String Vibrations Interesting thing I noticed just now playing my ukulele.
For those who don't know how a ukulele works, it has four strings: a high G followed by a lower C, E, and A. Holding down frets causes the strings to play progressively higher-pitched notes. Now, it is possible for two or more strings to play the same note. I've noticed that when this happens, playing one string will cause the others of the same pitch to vibrate, even without actually playing them. However, it's only when they are exactly the same note. If it's not the same note, it doesn't vibrate (at least not perceptibly). Why? If it's caused by the vibration from the string spreading outward, why would it matter what pitch the strings are relative to each other?
Perhaps it's a property of the nylon in the strings? After noticing this, I checked on my steel-stringed acoustic guitar, which definitely does not (perceptibly) do this. The sound of a ukulele (or any similar instrument - guitar, violin, etc) does not come from the strings themselves, but from the whole body of the instrument vibrating and moving the air which is in contact with it.
The vibrations are transmitted from the strings to the body of the instrument mainly through the bridge.
If you stop two strings so that they produce the same pitched note, the vibration of the bridge will cause both strings to vibrate if you pluck one of them.
This will also happen on an acoustic guitar, but in an electric guitar the sound is not physically produced by the body of the instrument vibrating. Instead, by magnetic pickups sense the vibration of the steel strings and the electrical signals are then amplified and sent to a loudspeaker.
The same effect happens in instruments like the piano, but the steel strings are at a higher tension than in plucked instruments and there is no visible vibration of the strings (except perhaps for the lowest bass notes) in normal playing.
The following is multiple choice question (with options) to answer.
A person playing a song on a string instrument makes strings | [
"mold",
"bawl",
"tear",
"shudder"
] | D | strumming a string can cause that string to vibrate |
OpenBookQA | OpenBookQA-1909 | electromagnetism, magnetic-fields, everyday-life
Title: How is magnetism ''conducted'' through a non-magnetic metal? I have a ball of metal about an inch in diameter and a concave disc of another metal (which is magnetic) around the ring of the disc (about $12 {\rm mm}$ in diameter). I don't know which metals they are. The ball is not magnetic on its own. That is paramagnetism, right?
The magnetic ring is strongly attracted to the surface of the ball, 'sticking' to it. However, I can stick a paperclip on the opposite side of the ball as if it has become magnetic itself, until I remove the magnetic ring from the ball.
When I wave the paperclip the same distance from only the ring itself, I feel no force at that distance.
Has the strong magnetic field of the ring caused a temporary magnetic alignment through the metal of the ball, allowing the paperclip to be attracted to it while the ring remains? The phenomenon you describe is ferromagnetism not paramagnetism.
Ferromagnetic materials like iron behave as if they contain many tiny bar magnets (called magnetic domains if you're interested to pursue this further), but because the magnet domains are aligned randomly the fields cancel out and there is no net magnetic field.
However if you put a ferromagnetic material in a magnetic field the external field will cause partial alignment of the magnetic domains. This induces a magnetic field in the originally unmagnetised iron, and that's why your paper clip sticks to the ball. However if you remove the external magnetic field the domains will go back to their original alignment, the net magnetic field will go back to zero and the paper clip will fall off again.
If you apply a very strong field and/or combine it with heating and cooling you can permanently change the alignment of the magnetic domains so they remain aligned when the external field is removed. This is how you make permanent magnets.
The following is multiple choice question (with options) to answer.
A ferromagnetic metal, such as in paper clips, can stick to other paper clips without hooking together | [
"when outside",
"when iron touches",
"when floating",
"when burned"
] | B | a paper clip is often made of ferromagnetic metals |
OpenBookQA | OpenBookQA-1910 | meteorology, weather-forecasting, barometric-pressure
Title: Do high pressure systems draw air towards them? I refer to the this very recent article, which quotes Andrew Watkins (Manager of Climate Prediction Services at the Australian Bureau of Meteorology).
My understanding has always been that air flows away from high pressure towards lower pressure, so the following quote from the referenced article confuses me. Can anyone explain it for me?
"There's been a big high pressure system drawing air in off the ocean,
keeping it a bit cooler for Sydney," Dr Watkins said. As Fred said, it's just an unfortunate word choice that makes you think the professor is suggesting air flows towards the high.
Indeed, a surface high pressure south of Sydney would be the circumstance to have the air circulate around it in such a way as to "draw" air onshore from off the shore... even as it's actually really flowing somewhat away from the high.
There's a long-range model forecast showing exactly this setup building after a strong low potentially passes by this week... and so Sydney may be held cooler again just in time for Boxing Day:
from www.pivotalweather.com
(This is only one model's long-range forecast, and the skill in such forecasts is quite low. I present it to show this scenario, not to make any forecast as to whether it'll actually happen next week)
You can see the green arrows are bringing air onshore. This link suggests current ocean surface temperatures are around 23°C (73°F). So that would likely reduce the temperature slightly (if you explore the plots at pivotalweather.com for Australia, it currently shows a forecast high closer to 23°C for the day, rather than nearer the 30s many spots in the area see tomorrow).
The following is multiple choice question (with options) to answer.
As air begins to chill, it may push out | [
"sand",
"liquids",
"fire",
"carrots"
] | B | dew is formed when water vapor condenses over night |
OpenBookQA | OpenBookQA-1911 | geophysics, plate-tectonics, geography, mountains, geomorphology
You will see that 416 Ma ago and before there was an active subduction boundary there inside the red polygon. So mountains were getting formed, the ocean in front of that boundary closed-up and disappear about ~240 Ma ago, giving the final push for the formation of a mountain range, that, if you follow it carefully, corresponds to the Ural mountains we know today.
The following is multiple choice question (with options) to answer.
This famous mountain range in Europe came about due to | [
"rocks floating on underground water sources",
"the work of an intelligent force",
"the folding of numerous layers of rock",
"the accumulation of soil over millions of years"
] | C | the Alps were formed by rock folding |
OpenBookQA | OpenBookQA-1912 | reproduction, sociality, fitness
Title: Which monkey species features two distinct male phenotypes? I remember coming across a popular science article years ago about a monkey species which featured two male genotypes: the first were good looking males who acquired social status (as alphas or betas) within the group and could thus achieve reproductive succes. The alternative (less frequent) phenotype achieved similar fitness by adopting an outgroup (omega) lurking rapist kind of reproductive strategy.
Does anybody know which species and whose observervations I could be referring to? I'm curious to find out if this was a valid observation and if any further research has been done on this phenomenon. Patas monkeys exhibit "sneak mating" where a male other than the resident male sires offspring. Resident males do sire more offspring than sneaker males, but both strategies do co-occur. I'm pretty sure there are other species that have a similar mating strategy as well.
The following is multiple choice question (with options) to answer.
Some monkey babies may be | [
"turned into canned meat",
"taken to a hospital",
"run out of the pact",
"taken care with two parents"
] | D | a monkey births live young |
OpenBookQA | OpenBookQA-1913 | mountains, rainfall
Title: Could a waterfall lashing onto a road lead to a landslide? Here is a video of a waterfall lashing on to a mountain road, with vehicles driving under it.
https://youtu.be/cHaguj--YBc
There appears to be a big hole carved out right next to the road, possibly by the force of the waterfall.
Is this a ticking time bomb for a landslide? Potentially, a landslide could occur. Whether it would be a minor slip or a major fall depends on the geological conditions at the site, the force of the water and the duration that the site is impacted by the water.
In the video in question, the rock face above the road appears competent, but there are not guarantees. The main issue would be is the water undermining the road which could cause a slip and the road to slide.
The more loose the geological material is, the easier it is to dislodge it. Once one item moves a chain of events can occur where additional items are dislodged and a slide occurs.
In addition to high pressure water dislodging material, water acts as a lubricant, making it easier for rocks and regolith to be dislodged.
To minimise the potential for a slide to occur in such a situation, the surface of the road would need to be sealed very well and a very good drainage system installed that would move the water away from the road and the slope below the road
The following is multiple choice question (with options) to answer.
Landslides effect things like | [
"cars",
"the sun",
"wind",
"communities"
] | D | a landslide is when gravity rapidly moves rocks or soil downhill especially after a rain storm |
OpenBookQA | OpenBookQA-1914 | magnetic-fields, earth
Title: Would a compass on its side point at the ground? From a point just north of the equator, A straight line to the Magnetic North would be through the earth. If a compass was turned on it's side, would the north pointing arrow point toward the ground along that straight line? A compass is usually used to find the direction of the horizontal magnetic field of Earth at that point. The needle of a compass is very light and thus its efficiency decreases when the compass is not in the horizontal plane at that point (due to gravity).Therefore, where the compass would point will become unpredictable. But, yes, in ideal conditions, the compass would point along the straight line joining that point to the north pole.
The following is multiple choice question (with options) to answer.
If you hold the compass sideways while at the south pole, where do the needles point? | [
"to the side",
"both down",
"both up",
"up and down"
] | D | a compass is a kind of tool for determining direction by pointing north |
OpenBookQA | OpenBookQA-1915 | telescope, mars
Have a look at this guide explaining how consumer-grade computer webcams can be used. It contains a neat comparison of a single frame and a stacked image.
Please note that I'm merely speculating as to which techiniques could be used to obtain such images. I can see that the author posted their email on the S&T site and that there's a comments section as well. Feel free to ask them yourself.
The following is multiple choice question (with options) to answer.
Cameras | [
"can take snapshots of friends wearing snapbacks",
"can be used for their microscopic properties",
"can be used for solving mysteries",
"can take friends on an adventure"
] | A | a camera is used for recording images |
OpenBookQA | OpenBookQA-1916 | water, equilibrium, evaporation, condensation
Title: Can there be net condensation into a pool of water? I'm curious about the equilibrium of evaporation and condensation. Given that the surface area of a dehumidifier's evaporation coil at 4C is proportional to the rate of condensation, how would the rate of evaporation and condensation of 4C water relate to its surface area?
Is there a condition, such as a warm humid room, where a pool of 4C water would increase in volume? Or, would evaporation always be dominant?
I can understand how rain droplets form but, they have a tiny surface area. As the surface area of a pool of water increases, could net condensation occur? Of course. On a hot, humid day, if you have a glass of ice water you'll get water droplets condensing onto the glass. The same happens onto the surface of the water, you just can't tell the difference between newly condensed water and the pre-existing water.
The following is multiple choice question (with options) to answer.
Evaporation of a pond can happen and will lead to what? | [
"a pond with more fish",
"a pond of less size",
"water level fluctuations constantly",
"frogs in the pond"
] | B | if a body of water loses all water then that body of water does not exist any more |
OpenBookQA | OpenBookQA-1917 | everyday-chemistry
Vinegar is used by many DIY people, but it is not a popular commercial product because it smells kind of bad, it's not very effective, and if it is mixed with bleach (WARNING) it can cause a serious health hazard. Also, 5% acetic acid is not extremely germicidal (it will work to kill bacteria in food after a few days); many spores will survive for hours in acetic acid. Vinegar is most effective against non-spore forming (gram negative) bacteria- which are often the more nasty kinds of bacteria (Salmonella, E. coli, Serratia, Pseudomona, etc.)... but it's less effective against spore forming (gram positive) bacteria (Candida, Bacillus, Streptococcus, Micrococcus, etc.). Again, it is an effective preservative in food... as is 5% ethanol (ie., beer). 50% acetic acid is much more effective and it works faster... as does 50% ethanol. pH is a factor, so vinegar is a bit more effective than ethanol, but in general, a high pH is much more effective than a low pH. So, ammonia or lye solutions are more effective than organic acids.
70% isopropanol and 60% ethanol are a common hand and wound disinfectants. They are fairly antimicrobial and antiviral, but again, spores (and other gram positive bacteria) can survive in dilute alcohols (for a little while).
The following is multiple choice question (with options) to answer.
Reducing bacteria in food prevents what? | [
"electricity",
"maladies",
"observation",
"signals"
] | B | reducing bacteria in food prevents illness in people |
OpenBookQA | OpenBookQA-1918 | comets, meteor
Title: Does this video catch an Eta Aquarid - Earth skimming meteor? I did a time-lapse animation looking towards the sunrise from Sydney, Australia on 25th of April. You can see it here around 1m 25s in (that link should jump to just before it appears very near where the Sun is about to rise):
http://www.youtube.com/watch?v=lqr_KuLd2-c&t=1m25s
It then proceeds towards the right of screen over around the next 21 seconds (around 10½ minutes) before disappearing off the right. You might need to send the video to full screen to see the small white 'bullet of haze' that is moving against a very wide background.
One of my first thoughts was that it might be a meteor skimming the upper atmosphere, but I was less confident of that given it seemed to be coming from the general direction of the Sun, and I'd thought that was a direction unlikely to produce meteors.
That was until I read Eta Aquarid Meteor Shower in 2016 which states:
The best time to view the Eta Aquarids is in the early mornings, right before dawn.
Well, at least that pins down the same time of day, if not the direction from which it came.
What is the likelyhood that this feature is a piece of comet debris that skimmed Earth's atmosphere? Things entering the atmosphere (whether a meteor or an atmosphere-skimming object) travel too fast to be visible for 10 minutes. Normally a pass of a satellite (at above atmosphere height) takes 2-3 minutes and most meteors are over in seconds.
Even the famous daylight fireball from the 1970s was over in a very short time.
I would guess what you have there is a plane at high altitude, though it's moving a bit slower than I would expect. (I'm open to suggestions.)
The following is multiple choice question (with options) to answer.
A comet is falling from the sky, a boy is watching and can tell that the light is brightest | [
"when it is far away",
"when it is under water",
"when it is upside down",
"when it is about to crash"
] | D | as a source of light becomes closer , that source will appear brighter |
OpenBookQA | OpenBookQA-1919 | material-science, everyday-life
Title: Paper stiffness As piece of paper is folded and unfolded, the stiffness of the sheet may seem to be greatly increased.
To those of you who don't recognise it: take a sheet of A4 paper, grasp one of the edges and move your hand vertically. Now fold the paper in half, unfold it and repeat.
Is anyone aware of any formal or heuristic explanation of what changed? You have stiffened the paper by greatly increasing its bending moment of intertia. This can occur in at least two ways:
1.) When you unfolded the paper, it still had some residual bend which made the paper form a very shallow 'V'. Even though shallow. it is much deeper than the thickness of the original paper.
2.) When you unfolded the paper, it still had some residual bend which made the paper form a very shallow 'V' which was very localized to the area next to the bend. Even if you refold the paper in the opposite way, to take out or minimize the original fold, there is still a shallow 'V'. Even though it might be much shallower than in case 1, it is much deeper than the thickness of the original paper.
In both cases, the increased resistance to bending comes from the new geometry of the paper, more specifially, the geometry of a cross-section of the paper which goes through the bend.
Think of the unbent paper as a beam. Its resistance to bending is proportional to b(d^3), where 'b' is the width of the beam and 'd' is the depth. If you take a piece of 8.5" x 11" piece of paper and lay it flat over a pencil on the table, the paper will flop so that both ends touch the table. The paper forms a beam: 'b' is 8.5" or 11" (depending on how you laid the paper) and 'd' is the thickness of the sheet (say, about one one-hundreth of an inch).
How to improve the stiffness and strength of this beam? Fold the paper, accordion-style, with sharp 1/2" folds. Then lay it across the pencil, so that the folds are perdendicular to the pencil.
The following is multiple choice question (with options) to answer.
A person takes a page out of a book and crumples it, so the page is | [
"flat",
"smooth",
"torn",
"round"
] | D | crumple means change shape from smooth into compacted by physical force |
OpenBookQA | OpenBookQA-1920 | respiration
Here is what happens at the molecular level.
The $\rm CN^-$ ions diffuse into the mitochondria. They have high affinity to the ferrous ion of the mitochondrial enzyme cytochrome c oxidase involved in the electron transport chain (ETC), one of the phases of cellular respiration where $\rm ATP$ is generated from $\rm NADH$ and $\rm FADH_2$. And it is this process that actually requires oxygen. The inhibited cytochrome c oxidase is of no good in transporting electrons, thus no $\rm ATP$ molecules are generated. The oxygen molecules waiting for those electrons remain empty handed resulting in the increase in the concentration of molecular oxygen. Remember, ETC occurs in almost all living cells except a few like RBC which get their major share of ATP from the highly inefficient anaerobic glycolysis. Also, $\rm ATP$ is the energy currency of our body and is required in a wide variety of bodily processes like osmotic balance, nerve impulse transmission, muscle contraction etc. With no $\rm ATP$ your heart and respiratory muscles can't contract, your medulla can't regulate breathing, your kidneys can't concentrate urine and the list goes on. Death is imminent if a high concentration of cyanide gets into your blood.
The symptoms of panic like tachypnea and tachycardia (that result due to low oxygen in blood) are not usually seen unless the victim himself knows he is poisoned. The end effects like cardiac and respiratory arrest, seizures and coma, however, are similar to those of suffocation.
For further read:
The Mechanism of Cyanide Intoxication and its Antagonism
The following is multiple choice question (with options) to answer.
Cellular respiration releases | [
"blood",
"waste",
"snot",
"feces"
] | B | all cells perform cellular respiration |
OpenBookQA | OpenBookQA-1921 | biochemistry, biophysics, bioenergetics
Title: Are there known life forms that are able to transform mechanical energy into chemical energy? Are there known life forms that are able to transform mechanical energy into chemical energy?
This question asks a similar subject, but more specific and has no answers.
The background of this question are thoughts about hypothetical life on tidally locked exoplanets of red dwarf stars, where light for photosynthesis is scarce but mechanical energy (storms and/or water currents) aplenty. There are no known life forms that use mechanical energy as a primary form of metabolic energy (i.e., for generic cellular functions). Many life forms are sensitive to mechanical disruption in some way, so they do utilize mechanical energy, but in a very limited fashion (@David's answer touches on this), and of course many organisms have life cycles that somehow depend on mechanical transportation (seed/spore dispersal, traveling on the wind or ocean currents, etc).
I think the main physical problem is that mechanical energy just isn't available to biological cells in a form that can be converted to substantial chemical energy. They are small, and tend to have other great benefits for being small.
To use an ocean wave as an example, there is very little or no perceptible movement for a cell in that wave, besides an apparent increase and decrease in the force of gravity. The top and bottom of the cell are moving together with the flow of water, so there is no differential to operate on.
An E. coli weighs about 1 picogram. If it could capture all of the energy from falling from 1km in the air on earth, assuming no uncaptured aerodynamic drag, that would be about 10-11 joules.
If there are ~3000 kJ/mol of energy available from burning glucose, that means about 5 × 10-21 joules per molecule of glucose, so about 20 billion glucose molecules, which sounds like a lot but it is only 1 femtogram, 0.1% the weight of the cell.
The following is multiple choice question (with options) to answer.
Materials that react with other substances to delivery energy, and derived from the remains of living organisms are | [
"excellent for the environment",
"a resource being depleted",
"never going to run out",
"hardly used anywhere by anyone"
] | B | natural gas is a nonrenewable resource |
OpenBookQA | OpenBookQA-1922 | thermodynamics, evaporation, gas, liquid-state
On the water surface, knowing the temperature, we can estimate the vapor pressure and vapor mixture fraction. Then there will be an diffusion process for the water vapor to move out and for the ambient air to move in. Because the water surface doesn't allow the air to further move, a circulation forms. When the water vapor moves out, the water vapor pressure drops, so more liquid water evaporates to fill up the loss of water vapor. The evaporation associates latent heat so water surface area temperature drops (you may see dew on the bowl wall). Then a heat transfer process starts which may initiate water circulation as well.
As this is complex, doing test might be a quick way to get the K value if you assume it is a constant, which is questionable.
The following is multiple choice question (with options) to answer.
What happens when available water decreases in an environment? | [
"growth",
"flooding",
"rain",
"dry spell"
] | D | drought means available water decreases in an environment |
OpenBookQA | OpenBookQA-1923 | thermodynamics, heat, visible-light, photons, everyday-life
That is more or less how I see it.
What steps are ok ?
And the main question , why is there light involved ?
I mean why cant we just have kinetic energy of the electrons and a changing magnetic field ? Why are there photons ?
If the electrons are in a high energy state why cant they just move faster instead of emitting a photon ???
Why is the light usually visible ? is that because of our structure of air ?
If the light is an electromagnetic wave why does the flame go up ? does that imply all electromagnetic waves go up ?? But electromagnetic waves are not influanced by gravity or buoyancy are they ??
What is the final destiny of the electrons and photons if the heat is gone ??
I am puzzled by this. You should take some time to read the links zhermes suggests. As a starting point:
Fire, or more accurately a flame, is a gas phase reaction. When you look at wood burning you are actually seeing wood heated by the flame giving off gas, and the flame is this gas reacting with oxygen.
When a molecule of combustible gas reacts with a molecule of oxygen the reaction products fly away with more energy than the original molecules had. This extra energy comes from the energy of reaction. The increased velocity of the reaction products corresponds to an increase in temperature according to the Maxwell-Boltzmann distribution.
The light comes from two sources. Firstly, the typical red/orange /yellow glow comes from particles of unburnt carbon in the flame. These are heated by collisions with the rapidly moving reaction products and glow by black body radiation. Secondly the most energetic reaction products collide hard enough to excite electronic transitions or even ionise gas molecules. As the excited molecules relax they may give off light that is characteristic of the transition. That's why you get specific colours e.g. green from copper, yellow from sodium etc.
The flame is not a plasma. Only a tiny tiny fraction of molecules and/or atoms in the flame are ionised.
The following is multiple choice question (with options) to answer.
Lightening could be a combustion of | [
"rain and ice",
"milk",
"seaweed",
"candy"
] | A | lightning can cause a forest fire |
OpenBookQA | OpenBookQA-1924 | everyday-chemistry
Title: How does a fire start? I know that fire in a few words is the exothermic reaction of a fuel with an oxidizing agent, but I can't fully understand what exactly happens to piece of wood when it is ignited. How do molecules start producing a flame? In other words, what is the chemistry behind the production of flame? https://www.youtube.com/watch?v=B0E4PX3e3RE It feels somewhat weird to answer my own question but I think this video describes exactly what I wanted. As it supports, when heat is applied to a piece of wood, some bonds of the molecules that make up wood, break and thus different compounds are formed. These compounds are not held back by some force and so they are released in the air. When these compounds meet atmospheric oxygen, under heat (=energy), they burn and thus more heat is released along with carbon dioxide and water. That stage can be described as ignition. Finally, this produced heat is able to preserve the fire.
The following is multiple choice question (with options) to answer.
When a wildfire happens what catches fire? | [
"rocks",
"timberland",
"water",
"rivers"
] | B | wildfire is when a forest catches fire |
OpenBookQA | OpenBookQA-1925 | species-identification, ornithology
Title: Bird identification from Nepal I just stumbeld across a picture and wonder which species it is?
I took the below picture of a bird, probably a raptor, in mid-January 2011, 7 pm, on the Annapurna Trek in Nepal. My altitude was around 2000 m.
Since I took the picture a long time ago I cannot recall any information about the size. Your image does not depict a predator, instead it's a scavenger. It's definitely a vulture, and by the looks of it a Griffon Vulture, which are a common siting in India.
The picture you provide is a bit grainy, and the apparently low-set sun colors the image somewhat yellow, but it does appear similar to below image of a Griffon vulture.
Griffon vulture. source: Vulture conservation in India and Nepal
The following is multiple choice question (with options) to answer.
Lisa was hiking in a rocky area and in a rock, she saw what looked like footprints made by a bird. But weirdly, they were in a rock. Where did they come from? | [
"The footprints were originally in mud or peat, but after a lot of time, the substance had been changed into rock",
"The rock was actually an asteroid",
"a very heavy bird made imprints in the rock.",
"a spaceship used a laser to make the etches in the rock"
] | A | An example of a fossil is a footprint in a rock |
OpenBookQA | OpenBookQA-1926 | fizzbuzz, audio, music, chuck
// Creates a major chord.
// @input float root : the root note of the chord.
fun void major(float root) {
root => oscPitch.freq => I.freq;
oscPitch.change(4) => III.freq;
oscPitch.change(3) => V.freq;
0 => VII.freq;
"major" => currentChord;
}
// Creates a minor chord.
// @input float root : the root note of the chord.
fun void minor(float root) {
root => oscPitch.freq => I.freq;
oscPitch.change(3) => III.freq;
oscPitch.change(4) => V.freq;
0 => VII.freq;
"minor" => currentChord;
}
// Creates a major7 chord.
// @input float root : the root note of the chord.
fun void major7(float root) {
root => oscPitch.freq => I.freq;
oscPitch.change(4) => III.freq;
oscPitch.change(3) => V.freq;
oscPitch.change(4) => VII.freq;
"major7" => currentChord;
}
// Sets the gain on the chord to make it audible.
fun void play() {
gain => I.gain;
gain => III.gain;
gain => V.gain;
gain => VII.gain;
}
// Sets the gain on the chord to make it inaudible.
fun void stop() {
mute => I.gain;
mute => III.gain;
mute => V.gain;
mute => VII.gain;
}
// @return string : the name of the current chord.
fun string getCurrentChord() { return currentChord; }
}
The following is multiple choice question (with options) to answer.
You may be able to make musical instruments from | [
"A paperclip",
"air",
"water",
"grass"
] | A | An example of playing a musical instrument is strumming a guitar string |
OpenBookQA | OpenBookQA-1927 | $$p_6 = \frac{1+9+36+84+126+126}{2^9} = \frac{382}{512} = \frac{191}{256}$$
Here's how this comes about: There are only two possible final states: certain drought, and certain rain. For any $k, 0 \leq k \leq 10$, let $p_k$ be the probability that the final state will be certain rain, given that the initial probability of rain is $\frac{k}{10}$. (Here, initial only means "current" since the process is homogeneous in time.)
Then, there is a simple set of linear equations relating the $p_k$. Suppose $k = 1$ initially. That is, the current rain probability is $\frac{1}{10}$. Then with probability $\frac{1}{10}$, the next rain probability will be $\frac{2}{10}$, and with probability $\frac{9}{10}$, the next rain probability will be $0$ (and the final state is certain drought). We can represent this as follows:
$$p_1 = \frac{1}{10} p_2 + \frac{9}{10} p_0$$
where $p_0 = 0$, naturally.
Now, let us suppose that $k = 2$ initially. Then with probability $\frac{2}{10}$, the next rain probability will be $\frac{3}{10}$, and with probability $\frac{8}{10}$, the next rain probability will be $\frac{1}{10}$. We can represent this as follows:
$$p_2 = \frac{2}{10} p_3 + \frac{8}{10} p_1$$
Proceeding along these lines, we can write equations of the form
$$p_k = \frac{k}{10} p_{k+1} + \frac{10-k}{10} p_{k-1} \qquad 1 \leq k \leq 9$$
The following is multiple choice question (with options) to answer.
Precipitation is the amount of | [
"dew point",
"raindrops",
"flooding",
"barometric pressure"
] | B | rainfall is the amount of rain an area receives |
OpenBookQA | OpenBookQA-1928 | Therefore, $$p_{11} = 0.5$$ is the probability of being sunny tomorrow, given that it is sunny today.
You would want to use your record to test the MC assumption.
Example 2:
Recall the weather pattern MC in example 1. You are planning a two-day holiday to begin in seven days, i.e., you are away on day $$7$$ and $$8$$. A travel insurance deal will pay you \$2500 if it rains on both days, nothing if not, and the premium is \$100. Should you buy this insurance if it is sunny today?
One way to make a decision would be to compare the expected pay-out with the premium. The actual return is
$$R = \begin{cases} 2500 & \text{if} \ X_7 = X_8 = 3 \\ 0 & \text{otherwise}, \end{cases}$$
where $$X_n$$ is the weather state on day $$n$$. Counting today as day $$0$$, the expected return is
\begin{align} E(R) &= 2500 \times P(X_7 = X_8 = 3 \vert X_0 = 1) \\ &= 2500P(X_8 = 3 \vert X_7 = 3, X_0 = 1)P(X_7 = 3 \vert X_0 = 1) \\ &= 2500P(X_8 = 3 \vert X_7 = 3) p^{(7)}_{13} \\ &= 2500p_{33}p^{(7)}_{13} \end{align}
Evaluation of the one number $$p^{(7)}_{13}$$ requires evaluation of $$\mathcal{P}^7$$, where $$\mathcal{P}^{(n)}$$ is the $$n$$-step transition matrix.
You will find that $$p^{(7)}_{13} = 0.2101$$, and $$p_{33} = 0.1$$, so $$E(R) = 52.52$$.
The following is multiple choice question (with options) to answer.
If I am out in the sun all day I should | [
"go naked",
"drink wine",
"avoid it occasionally",
"wear a coat"
] | C | if something is outside during the day then that something will receive sunlight |
OpenBookQA | OpenBookQA-1929 | meteorology, weather-forecasting
Title: Some website or institute with integrated statistics on forecasting the occurrence of rainbows I am a lay person in meteorology, maybe this is not the right place for my question, but I would like to ask then.
My question is simple: is there a website or institute that has integrated statistics on forecasting the occurrence of rainbows in different countries around the world? A rainbow is not a physical object that has a position. It is an optical phenomena that depends on your location relative to the sun and rain. If you are standing where your eyes can intercept the colored light, you are standing with your back to the sun and the sunlight is reflecting on raindrops in front of you. Someone else standing in a different location would not necessarily see a rainbow if they looked up at the same part of the sky.
From University of Illinois:
According to Descartes' calculations using laws of optics, the three stage refraction-reflection-refraction pattern that light undergoes when passing through a raindrop produces a concentration of outgoing rays along a line that is 42 degrees above the head of an observer's shadow. This concentration of light rays is the rainbow that we see.
Also this National Geographic article has a nice description:
Viewers on the ground can only see the light reflected by raindrops above the horizon. Because each person's horizon is a little different, no one actually sees a full rainbow from the ground. In fact, no one sees the same rainbow—each person has a different antisolar point, each person has a different horizon. Someone who appears below or near the "end" of a rainbow to one viewer will see another rainbow, extending from his or her own horizon.
What this means is that a rainbow is not really a meteorological occurrence that can be measured or catalogued, because you would get a different answer depending on your reference point. Lightning, in contrast, is a physical phenomena that has a precise location which can be determined and verified from multiple points of reference.
Rainbows are photographed and archived by enthusiasts, but it's really about artistic appreciation. While I have not looked into rainbow forecast services, a quick search shows some interesting resources, such as How to Predict Rainbows and Plan Photographs which has a link to a photography app that can plan for rainbows and here is a rainbow app you can install on your phone.
How Rainbows Happen also has a nice description (shown below) and some other useful resources.
The following is multiple choice question (with options) to answer.
In the intermediary before rain falls, observers may note | [
"beach weather",
"bright days",
"menacing skies",
"large moons"
] | C | grey clouds appear before precipitation |
OpenBookQA | OpenBookQA-1930 | atmosphere, geography
Title: How much atmoshphere is there compared to land and water We know our earth has 71% water and 29% land, but compared to that land and water, how much air do we have in our atmosphere?
I mean:
How big is our atmosphere
Is there any increase or decrease in the amount of atmosphere over time
Is there any change in percentage of oxygen over time 71% of Earth's surface is covered with water and 29% land.
Thinking in that regard, that's saying that on 29% of Earth's "surface" locations you have land below your feet, and in 71% of the locations, you have water. So to continue in such terms, you'd then ask... ok, what percentage of Earth's surface locations would have air above them!?! Well that's all of them. So to if you're comparing it with those percentages, I guess you'd have to say it's another 100%. Or, if we put them together into a full 3-dimensional surroundings at the surface, well it'd basically be 50% air, 36% water, 14% land.
But to compare how much of each there REALLY is, you need to include depth, getting some sort of 3 dimensional understanding of it. But the picture that reveals is certainly not the picture we are used to from daily experience. From the values I was able to find:
In terms of the room each takes up, the volume:
Surface water (oceans+lakes+rivers, glaciers, etc) is 1.4 billion km³
The inside of the Earth is about 1 trillion = 1000 billion km³
For the atmosphere, as mentioned in comments, it's a little more difficult, as the gases only gradually give way to space. You find less and less gas as you go up, but there's no set spot where there is none, as some tiny amount is always floating off into space. So where do you draw the line? A commonly used boundary between the atmosphere and space is the Karman line. This would lead to a volume of 53 billion km³ (using Earth's radius = 6371 km). Note that only about half of that is in the troposphere and stratosphere, which are perhaps the familiar zones of the atmosphere where weather and the ozone layer (and 95% of air molecules) reside.
The following is multiple choice question (with options) to answer.
Oceans cover 70% of the surface of what? | [
"the moon",
"the sun",
"wet planet",
"cities"
] | C | oceans cover 70% of the surface of the earth |
OpenBookQA | OpenBookQA-1931 | botany, color
Hypothesis 1
It should be remembered that chlorophyll is far from being the only pigment found in leaves. For example, carotenoids - which give yellow and reddish colors - are present in plant leaves. There are many carotenoids (according to Wikipedia there are over 1100 known, but that number will continue to grow). The biological roles of these carotenoids are also varied. In the course of the question, we may be interested, for example, in the photoprotective role of carotenoids. They are involved in the deactivation of reactive oxygen species (ROS). ROS can be formed during photosynthesis and can potentially be harmful to cells. Therefore, in conditions of excess solar radiation, plants can increase concentrations of carotenoids to prevent oxidative stress. It has already been pointed out to you in the comments that younger leaves look yellow - this is a common occurrence. The leaf is a very expensive organ, in the sense that the plant invests a lot of plastic substances in its development. So it makes sense that young, growing leaves get extra protection. That is, a young leaf that has not yet formed all the necessary structures (thick enough cuticle, efficient conductive system, etc.) is less efficient in terms of photosynthesis and therefore more susceptible to negative processes of photodamage. Increased concentrations of carotenoids, among other things, can reduce such risks. If you add to this the small thickness, it is understandable why young leaves often look more yellow.
Hypothesis 2
I have already said that leaves are expensive organs. They have a high protein content, which is very valuable to the plant. If a leaf is damaged or aged, there is a threat of irreversible loss of protein, which would be a great waste. Therefore, in such cases, plants trigger complex processes of removing valuable substances from the leaves. In particular, chlorophyll begins to break down, and the decomposition products are transported to the more durable parts of the plant. This is the reason why leaves change color in the fall, before defoliation. When the concentration of chlorophyll decreases, other pigments, such as carotenoids, increasingly affect leaf color. That's why damaged and old leaves often turn yellowish.
Although, I doubt that in the case of your plant, this process is often the cause for yellow leaves.
Hypothesis 3
The following is multiple choice question (with options) to answer.
What contains chlorophyll? | [
"plastic",
"water",
"green organelles",
"paper"
] | C | a chloroplast contains chlorophyll |
OpenBookQA | OpenBookQA-1932 | quantum-spin, atoms
The bonds between the atoms are obviously split when the paper is torn, but is there a way to put them back together?
the answer is yes, because this is precisely why paper recycling works. The incoming used paper is washed, to remove ink and other contaminants, and then left to soak in a particular solution (the composition of which partly determines the color, consistency, strength, etc. of the resulting paper), where it eventually turns into a slurry. Paper is made of long fibers of cellulose arranged essentially randomly; when immersed in water, those fibers spread out throughout the solution. Then the slurry is rolled into sheets and left to dry; as the water leaves, the cellulose fibers end up weakly attracted to each other (the "weak" part is important; it's why you can easily tear a piece of paper in the first place), which leads to a similar kind of random arrangement of weakly-bonded cellulose fibers that we start with.
The following is multiple choice question (with options) to answer.
Ways to reuse paper could be | [
"use as window cleaner",
"make a new dress",
"make a new shoe",
"build a new home"
] | A | creating paper requires cutting down trees |
OpenBookQA | OpenBookQA-1933 | civil-engineering
Other things that can be done is to place hay bales, or rocks, on the soil slope and on the slope above the deposited soil. These can help to reduce the speed of surface water running down the slope.
If hay bales are used they should be placed in a staggered, off-set pattern, so that long drainage channels, which would lead to the formation of erosion gullies, are not created by the bales.
Moonscaping of the upper natural slope, above the deposited soil slope would also help in preserving the deposited soil slope.
The following is multiple choice question (with options) to answer.
an area of low-lying ground near to a river is at risk of | [
"over fishing",
"balloon landings",
"droughts",
"H20 accumulation"
] | D | flood plains are located near rivers |
OpenBookQA | OpenBookQA-1934 | reproduction, asexual-reproduction
Title: can self-fertilization in flowers be called asexual reproduction? Suppose a flower having both male and female reproductive parts is self-fertilized then can this be called asexual reproduction...?I'm quite confused cause in this case the fusion of male and female gametes do take place but again the gametes are from the same parent....please help. According to this article from Berkeley, asexual reproduction is:
Any reproductive process that does not involve meiosis or syngamy
Using this definition of asexual reproduction and knowing self-fertilization involves meiosis and syngamy, it is not asexual.
The following is multiple choice question (with options) to answer.
A pollinating entity is one that move pollen from flower to flower and can be done by? | [
"a tiger",
"good for food",
"six legged entity",
"a heat source"
] | C | An insect is a pollinating animal |
OpenBookQA | OpenBookQA-1935 | zoology, sensation
Title: Can animals that rely heavily on sonar sense colour? Apparently there're species around as rely heavily on sonar to sense the world around them.
E.g. Bat, Dolphin, Whale ...
The humans, and other terrestrial beings in a lighted world are capable of distinguishing colour in varying degrees of acuity. Is this ability to sense colour in our environment applicable to species (terrestrial, avian, and marine) that rely heavily on sonar? Any animal using sound cannot sense color though sonar directly, though these animals are not entirely blind and can probably see colors in the infrared we can't.
Even on the darkest night there is some light around and all bats use this. Old World fruit bats have colour vision, which is useful to them as they are often quite active in daytime, roosting on trees in exposed positions, rather than tucked away in dark crevices like most microbats, which can see only in black-and-white.
Dolphins have additional senses in addition to seeing they can sense electrical fields. So if an animal has its eyes covered, they will seem to be able to do things you would not expect. Its not the same as seeing the color though.
Such animals using sonar can additionally sense density and hardness as well as other material attributes which would cause the acoustic properties of the material as well as movement.
A hard-bodied insect produces a different quality of echo from one with a soft body, so bats can distinguish between some different groups of insects in this way. They can also determine the size of the object.
What's really interesting is that even human beings can experience this unusual sense. Blind people have learned to echolocate by making clicks with their mouth, and there is a movement to teach this skill.
Anyone can try it. In just an hour or two I was able to tell how close I was to a wall, whether the wall was concrete. I couldn't play video games (2:20 on the link) or see colors though.
The following is multiple choice question (with options) to answer.
An animal that perhaps uses light to it's advantage is | [
"comb jellies",
"dolphins",
"cats",
"whales"
] | A | producing light is used for attracting prey by some deep sea animals |
OpenBookQA | OpenBookQA-1936 | With this relationship in mind, let’s take a look at statement 1.
## (1) The next time he prepares this dish, Malik will make half as many servings as he did the last time he prepared the dish.
Since we don’t know how many servings Malik made the last time, we still don’t know how many servings he will make the next time. So statement 1 is insufficient.
Let’s try the next statement.
## (2) Malik used 6 cups of pasta the last time he prepared this dish.
With this information, we can use the equation from our proportions before to find the number of serving Malik made the last time.
$4*6 = \frac{3}{2}s$
$24 = \frac{3}{2}s$
$24*\frac{2}{3} = s$
$s = 16$
Great! Now we know Malik prepared 16 servings of the dish last time. But, we still don’t know how many servings Malik is planning on preparing next time.
Insufficient.
## Let’s try both statements together:
Well, we know Malik made 16 servings last time from statement 2. We also know that the next time, Malik will make half as many servings as he did last time.
This means next time, Malik is planning on making 16/2 = 8 servings next time.
Since we have proportions relating servings to cups of pasta, we know we can find the number of cups of pasta Malik will need next time. So, we have all the information we need. Still, let’s finish off the question to make sure.
Plugging in 8 for the number of servings into our proportions equation, we have:
$4p = \frac{3}{2}*8$
$4p = 12$
$p = 3$
So, we know Malik will need 3 cups of pasta the next time he makes the dish. Both statements together were sufficient.
The following is multiple choice question (with options) to answer.
A burrito needs to be cooked so it | [
"has heat removed",
"is made hollow",
"is burned black",
"has heat applied"
] | D | cooking food requires adding heat energy |
OpenBookQA | OpenBookQA-1937 | neuroscience, neurophysiology, pain, peripheral-nervous-system
Title: Is it possible to feel pain in some part of a body, but the pain "feeling" is introduced somewhere else? Is it possible to feel pain in some part of a body, but that the cause of the pain is situated elsewhere in the body? For example, somebody feels pain in his toe, but it turns out that this pain is not signaled by nerves in his toe, but caused by a damaged nerve in the spinal cord, or somewhere in the brain. Yes, this is pretty common. Examples include
sciatica, pain felt down the back of a leg to the foot, from irritation to components of the sciatic nerve but commonly at the level of the sciatic nerve roots
angina pectoris, pain from myocardial ischaemia felt in the throat (Latin angina "infection of the throat"), arms, chest etc
shoulder tip pain from a subphrenic abscess
The clearest possible example of this is phantom limb pain, where pain is perceived to be arising from an amputated limb indicating that the pain is arising from central mechanisms.
The following is multiple choice question (with options) to answer.
An example of feeling could be | [
"the sun on the leaves of a plant",
"clothes on the thighs",
"water running in a river",
"air blowing trees around"
] | B | feeling is when an living thing senses through touch |
OpenBookQA | OpenBookQA-1938 | optics, geometric-optics, sensor
Are the pupil conjugates referring to the conjugates of A) the real pupil(Iris), B) The effective pupil or (C) the exit pupil of the eye (which i suppose is just a conjugate of the the "real" pupil).
My own understanding is we must have to image the "Effective pupil" as this will include abberations after the cornea, if we sucessfully image "The real pupil" on the Shack Hartmann this will not include aberrations from the cornea? As in Virens's answer "A conjugate to B" simply means A is an image surface when B is an object surface and contrariwise (I use the word "surface" here because it is almost always curved to some degree, even though to first order we model these surfaces as planes).
There is no way that this setup can measure anything other than the total aberration of the total eye system, including cornea, lens and aqueous humour. It is quite analogous to a double-pass interferometric test of a lens system as wontedly done with a Fizeau or Twyman-Green interferometer. The light passes through all the eye's components and there is no way of telling which part of the total wavefront aberration is induced by which part of the eye. If you think about the above in terms of what I describe below, it should become clear that you need to image the effective pupil as drawn in your diagram at the plane of the lenslets. In fact, strictly speaking, the talk of pupils in your document is not quite right and what you need to do is image the principal plane of the eye's optics onto the lenslet plane. However, this principal plane is almost always very near to the pupil and, as I discuss at the end, small errors in any of this discussion will not make a great deal of difference.
The following is multiple choice question (with options) to answer.
What enters the eye through the pupil? | [
"diverse light energy",
"light bacteria",
"air",
"drops of water"
] | A | light enters the eye through the pupil |
OpenBookQA | OpenBookQA-1939 | depends on the parameters of the orbit ($$a, \epsilon, \omega$$, i) and the Earth's equatorial radius $$R_E$$ and its $$J_2$$ term.
Let's use 6378137 meters for $$R_E$$ (from this answer) and 1.0826E-03 for $$J_2$$ (from this answer).
The satellite's period $$T$$ in your data table is 15.59029 revolutions per day, or about 5542 seconds. Then use:
$$\omega = \frac{2 \pi}{T} = 0.0011338 \ \text{sec}^{-1}.$$
$$a^3 = \frac{GM}{\omega^2}$$
where GM is Earth's standard gravitational parameter of about 3.986E+14 m^3/s^2. That makes $$a=$$ 6768601 meters, or an altitude of about 390 km.
Plug those all in to the first equation, and we get $$\omega_p = -1.2149 \times 10^{-6} \ \text{sec}^{-1}$$ If we multiply that by 60 days or 5184000 seconds, we get -6.298 which is almost exactly $$-2 \pi$$ or one complete cycle, just what the plot shows!
The argument of perihelion at first looks like it drifts steadily then flips by 180 degrees around day 85, but that's actually a smooth shape change since the eccentricity hits zero and bounces back. That looks like a natural precession as well, and not an orbital maneuver.
The following is multiple choice question (with options) to answer.
A satellite may make a revolution when | [
"plans a long trip",
"creates a new course",
"takes off into space",
"it travels around a thing"
] | D | a revolution is when something revolves around something else |
OpenBookQA | OpenBookQA-1940 | water, home-experiment, physical-chemistry
Argument: Oxygen is replaced by Carbon dioxide. So, there is the same amount of gas added than taken away. Therefore, heat alone most be responsible for the water level change.
Source of the Error: A simplified and wrong chemical equation is used, which does not take into account the quantitative changes. The chemical equation has to be balanced correctly. It is not true that each oxygen molecule is replaced by one carbon dioxide molecule during the burning process; two oxygen molecules result in one carbon dioxide molecule and two water molecules (which condense). Remember oxygen is present in the air as a diatomic molecule. [A reader clarifies the water condensation in an email to me as follows: If the experiment were done with the sealing fluid able to support a temperature greater than 212 F and the whole system held above this temperature then the water product of combustion would remain gaseous and the pressure within the vessel would increase as a result of three gaseous molecules for every two prior to combustion and the sealing fluid would be pushed out.]
Argument: Carbon dioxide is absorbed by the water. Thats why the oxygen depletion has an effect.
Source of the Error: This idea is triggered from the fact that water can be carbonized or that the oceans absorb much of the carbon dioxide in the air. But carbon dioxide is not absorbed so fast by water. The air would have to go through the water and pressure would need to be applied so that the carbon dioxide is absorbed during the short time span of the experiment.
Argument: The experiment can be explained by physics alone. During the heating stage, air escapes. Afterwards, the air volume decreases and pulls the water up.
Source of the Error: the argument could work, if indeed the heating of the air would produce enough pressure that some air could leave. In that case, some air would be lost through the water. But one can observe that the water level stays up even if everything has gone back to normal temperature (say 10 minutes). No bubbles can be seen.
Argument: It can not be that the oxygen depletion is responsible for the water raising, because the water does not rise immediately. The water rises only after the candle dims. If gas would be going away, this would lead to a steady rise of the water level, not the rapid rise at the end, when the candle goes out.
The following is multiple choice question (with options) to answer.
A gallon of water in a pot is placed over a fire. After an hour there will be | [
"a gallon of water",
"a solid ice block",
"two gallons of water",
"less water than before"
] | D | as the temperature of a liquid increases , the rate of evaporation of that liquid will increase |
OpenBookQA | OpenBookQA-1941 | botany
Title: Do any plants exhibit hormonal changes similar to puberty? Just what the title states.
Are there any plants/trees that exhibit a growth spurt at a definite interval after the shoot appears? In flowering plants (the angiosperms) there are several developmental transitions in the life of the plant. I won't list the plants, because the list includes pretty much all of them (although the magnitude in the change of developmental pace differs widely between taxa and environments).
First there is seed germination, which is controlled hormonally. Absence of germination is usually imposed by abscisic acid, whilst germination is caused at the appropriate time by gibberellic acid and ethylene (among other things; Holdsworth, Bentsink & Soppe, 2008).
Next, in many herbaceous species there is a transition between a spreading growth stage (e.g. rosette growth) and the flowering stage. The 'growth spurt' here is the differentiation and elongation of the flowering stem, and then subsequently the sudden flowering of buds. The transition is also controlled hormonally, by a variety of hormones including auxin (Zhao, 2010), gibberellic acid, ethylene (Schaller, 2012), and the long anticipated, recently confirmed florigen (Choi, 2012). Ethylene and abscisic acid then play important roles in the next developmental transition when seeds and fruits are produced and dehisced.
Small RNAs are also now being revealed to play a large role in controlling the timing of developmental, but they are upstream of the hormonal changes. In particular some key miRNAs are involved in auxin-based regulation of branching, and in embryogenesis (Nodine & Bartel, 2010), and RNA silencing is involved in the switch from rosette growth to flowering growth (reviewed in Poethig, 2009 and Baurle & Dean 2006).
The following is multiple choice question (with options) to answer.
Plants preparing for dormancy is a sign | [
"the earth is tilting",
"readiness an total alertness",
"extreme fatigue and tiredness",
"of a beautiful sunset"
] | A | An example of a seasonal change is plants becoming dormant in the winter |
OpenBookQA | OpenBookQA-1942 | food-chemistry
popcorn (kernels)
honey (jar of)
sugar (most forms)
alcohol (spirits like vodka, whiskey)
dried beans, dried lentils
I would not be planning to eat any of these stored for 25 years myself. And in general I'd suggest testing the items before trying them after 25 years or more (if you feel you must).
I would not expect cans or glass or plastic bottles of soda to be in good shape after anything like 25 years. The plastic might not survive without degrading. The can and plastic might react with the liquid over that timescale and the glass would survive but I'd be less optimistic about a sugar laced chemical soup like soda or cola not undergoing some changes. Hard to say.
If you want more info on this try this website.
Will it be ok to drink it, if it won't explode?
I would not try it. At best it soda would be flat and possibly not taste the same (chemical changes over that timescale ?) and at worst it could actually be harmful.
Exploding seems very unlikely.
Also, what about Snickers or a hamburger in a ziploc package with air sucked out of it with vacuum cleaner?
Air isn't the issue. There are bacteria that will happily live (and increase in numbers) on what's in the food. Well, it is food, after all. There are bacteria that will survive refrigeration as well. Over the timescale you're talking about I'd say it's all bets are off territory.
So: will Snickers, Hamburger in a ziploc, Bottle (or can) of Cola, all not opened, go crazy in 25 years? In 50 years?
All of those could be dangerous over such a long time period, IMO. At the very least they'd taste bad and at worst they'd kill you if you consumed them.
If so, can they go out of their packages and ruin the contents of the time capsule? If not, will it be safe to consume one of them?
Depends on the packaging. Glass would last indefinitely baring physical force or extreme of hot and cold (which might possibly cause fatigue cracking). The other wrappers would last pretty well (structurally), but 25 years is way past their design intentions. It would be a dice throw.
The following is multiple choice question (with options) to answer.
A soda can may become hot if it is close to an object used for | [
"mixing soda",
"cooking food",
"cooling food",
"pouring soda"
] | B | if an object is exposed to a source of heat then that conductor may become hot |
OpenBookQA | OpenBookQA-1943 | evolution, dna, natural-selection
It seems plausible to me that we (advanced life) could have a biological mechanism to "write" needed alterations into either our own DNA or our reproductive DNA over time, triggering the very specific evolutionary developments necessary to our survival without relying on random mutation.
My question:
Is this possible? Does any similar mechanism exist that we know of? If not, how can so many specific (advanced) evolutionary leaps be otherwise explained? This entire answer will be long, so read the short part first, then read the rest if you (or anyone else) is curious. Citations are included in the long section. I can include additional citations in the short section if needed.
Long Story Short
Your question touches on some common misconceptions about how the evolutionary process. Organisms don't "want" to evolve traits. Traits evolve through the biological processes of random mutation and natural selection.
Organisms do not "want" to evolve traits. (Well, OK, I'd love to evolve an extra pair of hands but that is not possible.) Natural selection works by modifying existing traits. Your turtle can stare all she wants at food out of reach but she will not evolve a longer neck. Instead, natural variation exists among neck lengths of the turtles because of variation of the genes that determine features related to overall boxy size. Those individuals with longer necks may be able to get a bit more food, live a little longer, and reproduce a little more. They will pass along their genes to their offspring, so perhaps more of their offspring will also have longer necks. Over many generations, the turtles may have somewhat longer necks.
A common misconception is that the traits of organisms are precisely adapted for a specific need. They are not, for a few reasons. First, natural selection occurs relative to the current environment. Adaptations that work well in one environment may not be so useful in another environment. Environments are rarely stable over evolutionary time so traits are subject to constant change.
Next, as mentioned above, natural selection can only work on what traits are present. While an extra set of arms would be handy, I am a tetrapod. My four appendages, along with the appendages of all other tetrapods, trace back to our common ancestor. The appendages of all tetrapods are modifications of that ancestral trait.
The following is multiple choice question (with options) to answer.
Metamorphosis changes an animal to a form in which it can | [
"communicate with others",
"eat",
"reproduce",
"hunt for food"
] | C | metamorphosis is when an animal changes from an immature form to an adult form |
OpenBookQA | OpenBookQA-1944 | materials
Title: What is the screen of a microwave made off? What material is the viewing screen of a microwave made of? I have been researching and all I find is that the holes on the screen are too small to let the bulky microwave radiation to pass through. The shielding in a microwave must be an electrically conductive material (usually thin steel), because it reflects microwaves.
The viewing window is also made of an electrically conductive material (thin steel), but has holes cut in it that are large enough to permit shorter wavelengths like light to pass through (so we can view it), but reflects long wavelengths like microwaves.
Microwave Oven Design on Wiki
The following is multiple choice question (with options) to answer.
Metal things are made of metal, glass things are made of glass, iron things, however, are made of what material? | [
"Iron",
"Plastic",
"candy",
"milk"
] | A | iron nails are made of iron |
OpenBookQA | OpenBookQA-1945 | terminology, meteorology
I've tried to illustrate the relationships with insolation and temperature here:
There are some other ways too:
Ecological. Scientists who study the behaviour of organisms (hibernation, blooming, etc.) adapt to the local climate, sometimes using 6 seasons in temperature zones, or only 2 in polar and tropical ones.
Agricultural. This would centre around the growing season and therefore, in North America and Europe at least, around frost.
Cultural. What people think of as 'summer', and what they do outdoors (say), generally seems to line up with local weather patterns. In my own experience, there's no need for these seasons to even be 3 month long; When I lived in Calgary, summer was July and August (hiking), and winter was December to March (skiing). Here's another example of a 6-season system, and a 3-season system, from the Aboriginal people of Australia, all based on weather.
Why do systems with later season starting dates prevail today? Perhaps because at mid-latitudes, the seasonal lag means that the start of seasonal weather is weeks later than the start of the 'insolation' period. In a system with no heat capacity, there would be no lag. In systems with high heat capacity, like the marine environment, the lag may be several months (Ibid.). Here's what the lag looks like in three mid-latitude cities:
The exact same effect happens on a diurnal (daily) basis too — the warmest part of the day is often not midday (or 1 pm in summer). As with the seasons, there are lots of other factors too, but the principle is the same.
These aren't mutually exclusive ways of looking at it — there's clearly lots of overlap here. Cultural notions of season are surely rooted in astronomy, weather, and agriculture.
The following is multiple choice question (with options) to answer.
A seasonal change may be expressed in | [
"birds flapping their wings",
"birds leaving a state",
"cows chewing their cud",
"horses being saddled up"
] | B | An example of a seasonal change is an animal growing thick fur for keeping warm in the winter |
OpenBookQA | OpenBookQA-1946 | telescope, optics
Title: Shouldn't this cause a fire? This website shows a telescope projecting the sun onto a blackboard: https://astronomyconnect.com/forums/articles/2-three-ways-to-safely-observe-the-sun.21/
Why isn't the board catching fire? You can easily start a fire on a sunny day by targeting the focal point of a magnifying glass onto something flammable. Why isn't the telescope in this picture doing the same thing?
Photo by Luis Fernández García It could start a fire if the screen is at the focal point of the optical system. That is how you light fires with a magnifying glass.
Here, the blackboard is likely away from the focal point, so you can see the shape of the eclipse (and you get a bigger image) without setting things on fire.
Although this is fairly safe, there are a few things to pay attention to:
If you do this, make sure nobody can walk between the telescope and the screen, because if they go near the focal point, they could get very hot.
Doing this will cause your telescope to heat up. If there are any plastic parts, they can melt.
The telescope in the picture seems to have a small opening. Don't do this with a big telescope. You don't need to collect a lot of light.
Not an answer to the question, but an important note: Observing the Sun is the most hazardous thing you can do in astronomy. Make sure you know what you are doing before you try.
The following is multiple choice question (with options) to answer.
A thing is on fire and afterwards it is | [
"salty",
"silly",
"sweet",
"seared"
] | D | fire causes burning |
OpenBookQA | OpenBookQA-1947 | organic-chemistry
Title: What are the minimal chemical requirements for a food which we all can eat? I've been puzzled by the following though experiment for the past few days:
I want to make my own food from scratch, but I do not know where to start from.
I want to be 100% sure that what I eat will never contains something that can damage my body. For example: If you buy something from the local market you can not be 100% sure that it's safe to eat. (99.9 % maybe... but that's not 100%)
I want to ask you to tell me, how can I make a food that I can eat, or should I say - live on it, for the rest of my life, that's 100% safe, I can control every aspect of it's creation and has many combinations of taste because I love diversity.
Thank you for your time : )
Edit:
Because I realized my question is very broad and indeed is a little... too much scientific I want to close it. But before I do so, here's what I had in mind:
I wanted to take some chemical elements, put them in a jar, run some electricity, heat, whatever through it, filter it, do some additional processing and eat it.
I wanted to know if the stomach can take it, because I was going to eat food that's not hard to digest. Considering the three basic biomolecules used by the body are carbohydrates, lipids, and proteins, you would need to consume these three molecules only. Now we can choose three substances.
Glucose, one of the most basic carbohydrates, is needed for ATP production, so that would be a food choice there.
Any oil or butter will provide lipids.
Protein comes from a variety of sources. Meat is typically though of as the best, but nuts are a pretty good source too.
Since nuts satisfy proteins and lipids, I'd say honey roasted peanuts are the most basic food you could live off of, if you replace pure glucose for the honey.
The following is multiple choice question (with options) to answer.
In order for food to keep safely, chemicals are used on them. This makes them what? | [
"be saltier",
"longer lasting",
"grow faster",
"taste sweeter"
] | B | bacteria cause food poisoning |
OpenBookQA | OpenBookQA-1948 | microbiology, bacteriology, photosynthesis
2H+ + 2e– → H2
So that the overall reaction becomes:
2H2O + hν → 2H2 + O2
(Of course, this will be at the expense of energy and reducing power for carbohydrate synthesis.)
Using Hydrogenase for the Catalysis
The enzyme, hydrogenase, can catalyse the reduction of hydrogen ions shown above. This enzyme is rare in eukaryotes and absent from higher plants. It is thought to be very ancient, and may have originally been involved in energy generation from hydrogen in early evolution. One of the roles it plays in contemporary organisms is in reoxidizing NADH generated during certain fermentations in bacteria such as the Clostridium family — hydrogen is the gas produced in gas gangrene caused by Clostridium perfringens.
Certain photosynthetic organisms — notably the microalga, Chlamydomonas reinhardtii, and the photosynthetic cyanobacteria — also contain a hydrogenase in their chloroplasts. The activity of this is generally low, but appears to be coupled to photosynthesis in certain circumstances. This is through the reduced ferredoxin produced at PSI transferring its electron to the iron or iron–nickel centre of the hydrogenase:
The following is multiple choice question (with options) to answer.
What is used by the gas given off by plants? | [
"computers",
"the respiratory system",
"helium balloons",
"other plants"
] | B | the respiratory system takes in oxygen from the air |
OpenBookQA | OpenBookQA-1949 | Now, we are also given:
{eq}\begin{align} W_h\ &=\ mg_h\\[0.3 cm] g_h\ &=\ \dfrac{W_h}{m}\\[0.3 cm] g_s\left (1-\dfrac{2h}{R}\right )\ &=\ \dfrac{24.31\ \rm N}{75.0\ \rm kg}\\[0.3 cm] \left (1-\dfrac{2h}{R}\right )\ &=\ \dfrac{0.324\ \rm m/s^2}{g_s}\\[0.3 cm] \left (1-\dfrac{2h}{R}\right )\ &=\ \dfrac{0.324\ \rm m/s^2}{5.19\ \rm m/s^2}\\[0.3 cm] \left (1-\dfrac{2h}{R}\right )\ &=\ 0.062\\[0.3 cm] \dfrac{2h}{3}\ &=\ 0.938\ \rm m\\[0.3 cm] R\ &=\ \dfrac{2h}{0.938\ \rm m}\\[0.3 cm] &=\ \dfrac{2\times 1.86\times 10^4\ \rm km}{0.938\ \rm m}\\[0.3 cm] &\approx \ 3.97\times 10^4\ \rm km\\[0.3 cm] \end{align} {/eq}
Now, the mass of the planet X can be calculated as follows:
The following is multiple choice question (with options) to answer.
the mass of a planet causes | [
"sunrise",
"earthquakes",
"sunset",
"matter to approach"
] | D | the mass of a planet causes the pull of gravity on that planet |
OpenBookQA | OpenBookQA-1950 | galactic-dynamics
("Gyr" = gigayear = 1 billion = $10^{9}$ years, in case that's not clear.)
The following is multiple choice question (with options) to answer.
In a single year, a giant globe will do this to a giant star. | [
"fight",
"burn",
"circle",
"explode"
] | C | the Earth revolves around the sun |
OpenBookQA | OpenBookQA-1951 | zoology, ethology, behaviour, psychology, death
I can't prove it to you, but I know that my Beagle had a rich emotional life. I know this because I spent huge amounts of time with him. He was a close friend of mine. I would just as soon question whether my wife has real emotions as my dog. I can't prove that my wife's emotions are real either, but I don't have to. It would be silly to assume that everything she shares with me is some sort of evolutionary programming, and not real emotion. Now, when I extend this to cetaceans, I must admit that I don't have any friends in those circles. So I can only guess.
The following is multiple choice question (with options) to answer.
The more active an animal is | [
"their water level will stay steady",
"the less H2O they need to stay hydrated",
"the more H20 they should take in",
"the less likely they are to sweat or pant"
] | C | as the activity of an animal increases , the amount of water in an animal 's body in that environment will decrease |
OpenBookQA | OpenBookQA-1952 | c#, game, console, community-challenge
public override GameScreen Run()
{
Console.Clear();
if (_player.HasItem("Living Room badge"))
{
Write("You walk into the kitchen, your mom looks too happy.");
Write(_player.Name + ", finally! So you cleaned up everything! Great! So we're ready for NewYear's party!");
MenuItems = new Dictionary<string, Func<GameScreen>> { { "Collapse and wake up when the Holidays are over", () => null } };
}
else
{
Write("You walk into the kitchen, your mom is cleaning up dishes.");
Write(_player.Name + "! What are you doing here? I told you to clean up! Come back when you're done!");
}
return Menu();
}
}
Output:
You wake up with a headache, confused and surrounded with empty bottles, chips and pretzels.
[ENTER]
Ah! There you are! Time to clean up this mess! Here's a [GREEN BAG], meet you in the [KITCHEN] in 30 minutes!
[ENTER]
Received 'GREEN BAG'!
(A general-purpose garbage bag.)
You get up, pick up the bag and remember your name (enter it!):
Uh, don't you remember your name?
Ok nevermind, we'll call you Rudolph.
[ENTER]
What do you do?
[1] Pick up empty bottles, chips and pretzels
[2] Go to [KITCHEN]
Selection?
2
You walk into the kitchen, your mom is cleaning up dishes.
[ENTER]
Rudolph! What are you doing here? I told you to clean up! Come back when you're
done!
[ENTER]
What do you do?
[1] Go to [LIVING ROOM]
Selection?
1
What do you do?
[1] Pick up empty bottles, chips and pretzels
[2] Go to [KITCHEN]
Selection?
1
Received 'Living Room badge'!
(A badge that certifies the living room has been cleaned up.)
What do you do?
[1] Go to [KITCHEN]
Selection?
1
You walk into the kitchen, your mom looks too happy.
[ENTER]
The following is multiple choice question (with options) to answer.
A boy wants to collect clams for supper and must therefore spend time | [
"in lake shallows",
"in desert sands",
"in rocky hills",
"in sea depths"
] | D | clams live at the bottom of the ocean |
OpenBookQA | OpenBookQA-1953 | telescope, newtonian-telescope
Bottom line: don't buy a refractor because you "want to watch planets". But do buy a refractor if simplicity of use and the low maintenance are very important to you (and you don't care much about price).
A decent refractor on an excellent mount can do pretty good astrophotography. More on that below.
CATADIOPTRICS (CASSEGRAIN, MAKSUTOV, DALL-KIRKHAM, RITCHIE-CHRETIEN)
Broadly speaking, these are for astrophotography (not always, but usually). But can you do visual astronomy with them? Sure. It's just that it's easier to optimize them for photo, with this design.
Usually, they come installed on a motorized mount. All but the very cheapest ones have a computer on-board; you just punch the name of the object into the remote control, and the scope will turn around automatically to face the object. Sounds cool, right?
Well, I am going to say something a little controversial here: this is not a good place to start.
First off, astrophotography has an extremely steep learning curve. It's very easy to take a little blurry photo of Jupiter that will impress nobody. It's very hard to take a great, high resolution photo like these:
http://www.acquerra.com.au/astro/
The skills and knowledge required to take that kind of photos are more easily acquired by doing purely visual astronomy, on a dob or whatever, for a couple years or more. Also, the equipment required for that sort of stunt costs many thousands of dollars - your cheap little Cassegrain cannot do it.
So why buy a small Cass? Well, if you have an overwhelming interest in astrophoto, and are prepared to deal with the difficult learning, then go ahead. But realize that the first images are not going to be very impressive, and the motorized mount will not teach you some valuable skills that you would acquire more easily pushing a dob around and keeping your eye plugged into the ocular for a while. Also, money spent on the motorized mount is money NOT spent on aperture, and the aperture is so important for overall performance.
The following is multiple choice question (with options) to answer.
A good candidate for putting sticking a reflector to is | [
"a peaceful guru",
"a sedan",
"a steak",
"a cat"
] | B | a reflector is used to reflect light especially on vehicles |
OpenBookQA | OpenBookQA-1954 | dna, dna-sequencing, genomes, human-genome, mouse
I hope this is understandable, if you need any clarification on terms, please ask :)
The following is multiple choice question (with options) to answer.
Mice | [
"abandon their offspring",
"hatch their young",
"lay eggs",
"nurse their offspring"
] | D | a mouse gives birth to live young |
OpenBookQA | OpenBookQA-1955 | fluid-mechanics
Title: How to calculate divided irrigation discharge from a Parshall flume
How do I calculate the discharge from a Parshall flume that flow over a bulkhead (XY) into three partitions (A, B and C) divided 25%/50%/25%. There is no restriction of flow when the pipe gates are open (the incoming volume does not exceed the capacity in any of the partitions). The partitions A & C feed 8" pipe, while the partition B feeds a 10" pipe. When either A or B partitions are closed (using gates A1 and C1), a downstream gate (A2 and C2) can be opened to dump that partition's portion into the 10" pipe (Section C).
If gate C1 is closed (effectively shutting off the water to that pipe), and the downstream gate C2 is closed, what percentage of the water goes into Pipe A and B? (My guess is A 33% and B 66%)
If gate C1 is closed (effectively shutting off the water to that pipe), and the downstream gate C2 is open, what percentage of the water goes into Pipe A and B? (My guess is A 25% and B 75%)
Thanks, Chris Hydraulics get complicated fast, the beaty of weirs (that's the function of your bulkhead hear) is that you simplify the hydraulics, as you separate the flow upstream of the weir from the flow conditions downstream the weir: As long as water level downstream is a bit below the crest, flow conditions upstream can be calculated backwards from the weir withour regarding downstream conditions. This is why you can build flow distributing structures as per your drawing: Flow into one compartment depends only on weir length (again, only so long as the water level downstream is below the weir crest). You "pay" for this with hydraulic losses.
Your guesses is correct, provided two things:
the wall partinioning B & C is higher than the resulting water level in those compartments.
There's enough distance between upstream of the bulkhead for the flow to evenly distribute, or the flow velocity is low (how much distance? How low? I don't know. You want even distribution along the bulkhead). Given the shape of your flume upstream, I'd assume that you are good.
The following is multiple choice question (with options) to answer.
Diverting overflow from a reservoir through pipes generates | [
"The Colorado River",
"hydropower",
"The Hoover Dam",
"solar power"
] | B | hydropower requires damming a river |
OpenBookQA | OpenBookQA-1956 | temperature, sun, light, equator, insolation
Title: Why does the intensity of sunlight depend on your latitude? People at the equator get to bask in more sunlight than Santa Clause and other inhabitants of the arctic regions. Not quite as pronounced, but they get more than me too.
Why is the sunlight more intense closer to the equator and less intense farther away from it?
When I posted this question, I was not thinking about the possible ambiguities, such as "Are you talking about the exposure across a surface area with some non-perpendicular angle to the sun," or "Are you talking about the light gathered by an optic facing the sun?" There is a difference. Since "basking in sunlight" was the example use case, let us assume exposure across a surface area which is lying on the ground. As noted in the comments, this answer applies to things like sun-bathing and solar panels, but it does not apply so much to a specific point-receptor like an eyeball. If all objects in question are pointing directly at the sun, then the angle of incidence is equal for all of them and this answer does not apply.
For an optic facing its target, the amount of atmosphere that the light passes through is a very large influencer. At higher latitudes, the sun is not directly overhead, and so the light is not coming straight down through the path of least atmosphere. Instead, it comes in at an angle, passing through more of the atmosphere before it gets to you.
For sun-bathers, solar panels, and the ground in general, the sunlight absorbed and reflected does depend very much on what is described in this answer. For that reason, more expensive solar panels are mounted on devices which alter their angle to face the sun for increased light exposure. And a sun-bather could likewise increase their exposure by mounting their platform at an angle. This is the direction the rest of the answer will take.
The answer is similar to the answer to some other questions, such as "Why does the solar power intensity change with the season?" and "Why does the solar intensity change with the height of the sun in the sky (ie: with the time of day)?"
The very short, non-technical version (tl;dr)
Each unit (think "beam of sunlight") is spread over a larger area.
That might not seem intuitive at first, but that is the answer in a nutshell. To see why, continue to the long version.
The following is multiple choice question (with options) to answer.
Sunlight is important for | [
"communities",
"pollution",
"space",
"bats"
] | A | the sun transfers solar energy from itself to the Earth through sunlight |
OpenBookQA | OpenBookQA-1957 | thermodynamics, phase-transition, states-of-matter
So in theory, you can have 100% ice that is at melting temperature. If you apply exactly the energy required for that amount of ice to transition to water, then you would have 100% water that is at the exact same temperature. If instead you only applied 50% of the energy required to melt that quantity of ice, then you would have a mixture of 50% ice and 50% water, still at the same temperature. (Of course in reality the temperature will not be perfectly even; you're much more likely to have ice at a range of temperatures from just below up to the melting point and water at a range of temperatures from the melting point to a bit above)
So there's a clear boundary in that each given "bit" of H2O is either water or ice, there's no state that is "in between ice and water" that is passed through on the way to melting the ice. The halfway point to melting a block of ice does not have all of the ice with "partially weakened bonds", or anything like that. But the transition of a large chunk of ice into water is a gradual process, not something that happens at a clear instant - more of the ice gradually undergoes the (sharp) transition to water as more energy is gradually added.
The following is multiple choice question (with options) to answer.
When ice is heated in a pan to 100 degrees Fahrenheit it will melt and then | [
"be agitated",
"refreeze",
"spin",
"do nothing"
] | A | boiling is when liquids are heated above their boiling point |
OpenBookQA | OpenBookQA-1958 | waves, electromagnetic-radiation, acoustics, interference, noise
It's two different things that are kind of analogous. I can't say it's impossible but it looks difficult.
The following is multiple choice question (with options) to answer.
An inexhaustible resource could be | [
"sand clay",
"fossil fuels",
"cars",
"metals"
] | A | wind is an inexhaustible resource |
OpenBookQA | OpenBookQA-1959 | meteorology, severe-weather
The lack of rich low-level moisture is due in large part to the lack of accessibility from warmer moisture sources, particularly the Gulf of Mexico; the Rockies provide a barrier to much of the moisture reaching further west.
As you note, parts of Wyoming and Montana do see supercells and tornadoes a bit more often... but on a good topographic map, fair parts of those states are east of the Continental Divide, and so still on an "upsloping" area and thereby not blocked by sinking regions which prevent full moisture progress. They're still less-tornado prone due to elevation and increased distance from moisture, but it does happen.
The desert southwest also does manage to get monsoon moisture sneaking around the terrain further south... but further north that monsoon moisture sees additional blocking by the more elevated terrain across Nevada and Utah. (And in the southwest, a different key ingredient in tornadic supercell development is typically missing in the summer monsoon: upper-air winds sufficient for supercell development)
The Pacific Coast does see a few occasional tornadoes. But from what I've seen, they typically form from smaller storms with much less classical and intense mesocyclones. As you mention, they're a bit more in line with cold-core setups, which usually produce weaker short-lived tornadoes than classic supercells of the Plains and on east. If you plug in the events you speak of into SPCs Severe Weather Events archive, [pick the date, then click Obs and Mesoanalysis on the left, then use the dropdowns to find various parameters]
you can see that CAPE was typically very meager (well short of 1000 J/kg) and the storm structure quite weak in reflectivity in comparison to a classic supercell, more indicative of such cold-core setups.
Capping inversions may be helpful to "keep the lid on the pot" if you have strong CAPE (and therefore quality moisture) and intense updrafts to erode the cap during the day. But as it is, there isn't enough moisture typically for the cap to be a positive factor.
The following is multiple choice question (with options) to answer.
An arid region has very little | [
"rocks",
"heat",
"food",
"sand"
] | C | a desert environment contains very little food |
OpenBookQA | OpenBookQA-1960 | ecology
Title: Statement about Tropical Rainforests I made a statement about tropical rainforests, and I want to know if it's somewhat true or not:
The soil in tropical rainforests is not exceptionally fertile, because it contains few minerals. The reason that a tropical rainforest has a huge amount of vegetation is because of the quick mineralisation. If a dead leaf falls onto the ground, it immediately gets turned into minerals, which the plants immediately use for sustaining theirselves There are many websites which describe this phenomenon. They all seem to confirm the basic premise of the question: in tropical rain forests most of the minerals are held in the biomass and rapid decomposition contributes to the recycling of these nutrients for new growth. One example is here.
Tropical rainforests are noted for the rapid nutrient cycling that occurs on the ground. In the tropics, leaves fall and decompose rapidly. The roots of the trees are on the surface of the soil, and form a thick mat which absorbs the nutrients before they reach the soil (or before the rain can carry them away). The presence of roots on the surface is a common phenomenon in all mature forests; trees that come along later in succession win out in competition for nutrients by placing their roots over top of the competitors, and this pattern is seen in the temperate rainforest as well. What does not occur in the temperate rainforest, however, is a rapid cycling of nutrients. Because of the cold conditions and the acidity released by decomposing coniferous needles on the forest floor, decomposition is much slower. More of the nutrients are found in the soil here than would be the case in a tropical forest, although like the tropical forest most of the nutrients are held in the plants and animals themselves.
I looked for actual evidence of these differences in rates of decomposition and I found this:
Salinas, N. et al. (2011) The sensitivity of tropical leaf litter decomposition to temperature: results from a large-scale leaf translocation experiment along an elevation gradient in Peruvian forests. New Phytologist 189: 967-977
The following is multiple choice question (with options) to answer.
What does a desert environment receive less of than a forest? | [
"visitors",
"H2O fall",
"wind",
"recognition"
] | B | a forest environment receives more rainfall than a desert |
OpenBookQA | OpenBookQA-1961 | energy, visible-light
You can see the "brightness" at the end of the fiber - the construction (with graded index along the sides) drives all the light to this one interface where the light can escape.
The following is multiple choice question (with options) to answer.
Light can easily be seen bouncing off of a | [
"paper bag",
"pencil",
"overhead sign",
"cardboard box"
] | C | when light hits a reflective object , that light bounces off that object |
OpenBookQA | OpenBookQA-1962 | zoology, ichthyology, marine-biology
Switek goes on to to talk about exceptions in some marine mammals:
At this point some of you might raise the point that living pinnipeds like seals and sea lions move in a side-to-side motion underwater. That may be true on a superficial level, but pinnipeds primarily use their modified limbs (hindlimbs in seals and forelimbs in sea lions) to move through the water; they aren’t relying on propulsion from a large fluke or caudal fin providing most of the propulsion with the front fins/limbs providing lift and allowing for change in direction. This diversity of strategies in living marine mammals suggests differing situations encountered by differing ancestors with their own suites of characteristics, but in the case of whales it seems that their ancestors were best fitted to move by undulating their spinal column and using their limbs to provide some extra propulsion/direction.
The following is multiple choice question (with options) to answer.
an animal that moves quickly through the water is a | [
"swordfish",
"snail",
"tadpole",
"sea horses"
] | A | large fins can be used to move quickly through water |
OpenBookQA | OpenBookQA-1963 | water, materials
Title: Hygroscopic material absorption level I live in a high humidity location and every winter, mold forms on one of my walls due to water sticking on it during the cold times. This also ruins the paint.
I found out that certain materials absorb water from the air, so I decided to make my own dehumidifier based on sea salt. The problem is alleviated slightly, but not fully - the salt becomes moist, but I think after a certain point it just can't absorb any more humidity.
So I was wondering how much salt I would need to bring the humidity in my room to a normal level.
I looked for things like "hygroscopic materials water absorption levels" on Google, but I did not have much luck.
What I am looking for is a formula like:
X kg of sea salt will absorb Y kg of water at Z% humidity
I have no background in chemistry, unfortunately, so I am not even sure if I am searching for this formula using the right terms. I tried to do something similar when I had a humid car.
In chemistry, we often use $\ce{CaSO4}$ or anhydrite to serve as a desiccant. You could probably get cost-effective plaster for similar purposes. You could also get gypsum and heat it to generate plaster of Paris yourself.
As you're probably aware, people also use silica gel in products (and food) to minimize water content.
Either material should be much better as a desiccant than regular salt.
One key criteria is to increase the surface area - make sure the material is a fine powder and enclose it in something porous. I've seen people use various cloth materials, paper towels, etc.
As to how much you need, you can work out how much it will eventually absorb. If I take plaster of Paris to gypsum, each mole of $\ce{CaSO4}$ will take ~1.5 moles of water. So for every 136.14 g of anhydrite or ~145.15 g of plaster, you can absorb ~27 g of water. (I use ~ here, since I'm not convinced that regular plaster of Paris will be completely $\ce{CaSO4*0.5H2O}$.. some will likely already have extra water in it.)
The following is multiple choice question (with options) to answer.
High humidity can damage materials which | [
"must remain dry to function",
"will dry out unless they are soaked in water",
"depend on abundance amounts of water vapor",
"need to be kept wet"
] | A | An example of moisture is water vapor in the atmosphere |
OpenBookQA | OpenBookQA-1964 | evolution, zoology
Let's say the environmental challenge for two different kinds of carnivore (let's call them Bogs and Dats) is to catch Mophers. Both Bogs and Dats initially have the same medium-to-short muzzles. Some Bog individuals figure out that they can dig Mophers out of their burrows, and some Dat individuals figure out that they can catch Mophers at night when the Mophers leave their burrows. Both strategies are successful. Some Bogs happen to have longer muzzles than their cousins, and find it turns out that longer muzzles work synergistically with the digging strategy, allowing Bogs to stick their noses into the Mopher burrows to grab escaping Mophers. The resulting fitness advantage results in an increase of the long-muzzle trait in further generations of Bogs. Note that in this scenario it is the adaptive behavioral strategy that creates selective pressure that favors a particular genetic adaptation.
Dats on the other hand, because of their nocturnal hunting strategy, benefit from improved night vision; and long muzzles don't provide any fitness advantage to Dats because Dats don't dig Mophers from their burrows. As long as Bogs and Dats don't hybridize, they will most likely end up with long and short muzzles respectively.
The Waddington effect, also called “Genetic Assimilation”, is somewhat more direct:
An environmental stress causes a proportion of a population to develop one or more abnormal traits, by interfering with embryological development.
If there is a selective pressure in the environment that favors some subset of those traits, individuals whose genetic makeup makes them more likely to develop that subset of traits, those individuals are likely to produce more descendants than other members of the population.
If being “more likely to develop” that subset of traits results from a weakening of genetically determined development controls that would otherwise prevent development of that subset of traits, then the subset of traits can eventually become the normal phenotype.
The following is multiple choice question (with options) to answer.
A creature can hide in plain sight from predators because | [
"it burns",
"it misdirects",
"it cries",
"it stinks"
] | B | camouflage is a kind of protection against predators |
OpenBookQA | OpenBookQA-1965 | home-experiment, oxidation-state
Title: the perfect campfire As far as chemistry goes, there are laws or observations that can be useful to determine the perfect shape and disposition of the wood in a campfire ?
For example what chemistry says about the 2 most popular "shapes"
teepee
log cabin
or even other variations such as the swedish stove ( 1 log with the top splitted in multiple segments )
The properties that I'm looking for:
- easy to start
- long lasting
The properties that I would like to have but I can discard:
- significant heat generation From many years as a trained firefighter, I can tell you that there is certainly science involved. There are a number of very heavy calculations for calculating things like solid combustible burn time and heat release rates for combustible materials, which might possibly be useful to predict the perfect shape, fuel size and arrangement for a campfire, but are probably well beyond the scope of producing the perfect sausage sizzle. However, a number of key factors that influence fire behaviour, and which must be considered in building the best campfire include:
The following is multiple choice question (with options) to answer.
A person puts a potato in some embers on the edge of a campfire. The embers are | [
"hording thermal energy for later",
"taking in the warmth",
"meant for staying cool",
"doing a thermal release"
] | D | an exothermic reaction increases the amount of heat |
OpenBookQA | OpenBookQA-1966 | That would be a total of 5x30 + 3x40 + 2x60 = 390 plants (with an arbitrary factor that we'll set to 1 without loss of generality).
The amount of highbush is 5x30 = 150.
The amount of lowbush is 3x40 = 120.
The amount of hybrid is 2x60 = 120.
If the opossums didn't care, they would likely eat blueberries in this ratio (null hypothesis H0).
The total that we have observed the opossums to eat is 5% x 150 + 10% x 120 + 20% x 120 = 43.5 plants.
They eat 5% large, which a corresponding fraction of 5% x 150 / (5% x 150 + 10% x 120 + 20% x 120) = 17%
They eat 10% low for 10% x 120 / (5% x 150 + 10% x 120 + 20% x 120) = 28%
They eat 20% hybrid for 20% x 120 / (5% x 150 + 10% x 120 + 20% x 120) = 55%.
Checking... yes the total is 100%.
What we see is that the opossums prefer hybrid by far.
Small blueberries are their second choice.
Last edited:
#### anemone
##### MHB POTW Director
Staff member
Hi anemone!
What do you mean by the symbol E?
Anyway, you've found that the opossums eat 45.8% large and 54.2% small for a total of 100%.
But... what happened to the hybrid blueberries?
By the symbol E, I meant the blueberries (all 3 types of them) that are eaten by opossums...
That would be a total of 5x30 + 3x40 + 2x60 = 390 plants (with an arbitrary factor that we'll set to 1 without loss of generality).
The amount of highbush is 5x30 = 150.
The amount of lowbush is 3x40 = 120.
The amount of hybrid is 2x60 = 120.
If the opossums didn't care, they would likely eat blueberries in this ratio (null hypothesis H0).
The following is multiple choice question (with options) to answer.
A person rescues a small chipmunk and it requires nourishment. The person obtains | [
"cold cuts",
"turkey legs",
"tree pips",
"red sauce"
] | C | a chipmunk eats acorns |
OpenBookQA | OpenBookQA-1967 | thermodynamics, energy, home-experiment
Additionally, what power rating could I go down to if I were to increase the time to boil by 50%?
As above, if 2000 Watt nominal input gives an ~= 45 minutes to boiling, and the target was < 1 hour, then you'd expect an increase in time to boiling by a factor of 1.5 to 90 minutes to require ABOUT 2000 x 45/90 = 1000 Watts electrical input if thermal losses are able to be scaled down proportionally. With "normal" cooking energy sources adding insulation is problematic but with induction heating adding another towel wrapper and a layer of padding on top is actually feasible. If losses cannot be scaled down then see above calculations for assumed losses and recalculate accordingly.
The following is multiple choice question (with options) to answer.
A pot of potatoes is left on a stove at medium heat. The person cooking forgets that the potatoes are cooking and they cook for twelve hours. When the person checks on them after half a day, | [
"they are cold",
"they are fine",
"they are singed",
"they are lukewarm"
] | C | if too much heat is transferred to an object then that object may burn |
OpenBookQA | OpenBookQA-1968 | electricity
Title: Can touching a single power line (on the street) kill you? Statement: You need to touch two power lines at the same time to get electrocuted. I am kinda doubting this now because, in the video linked below, it looks like the person is only touching one line but still gets an electric shock. Is this possible? and also the person is on a tree and aren't trees insulators? This video isn't sensitive or anything, it actually funny, so please don't hesitate to watch. Thanks!
Video Unless there is sufficient insulation (electrical impedance) between you and the earth when you touch a high voltage wire, yes you may get electrocuted. This is because most electrical power systems in the world are earth grounded (referenced to earth). The higher the voltage the greater the impedance to between you and earth ground needs to be. At 60 Hz it only takes 50-100 mA of current in a path through the heart to cause ventricular fibrillation.
If you are isolated from ground and touching two wires with your bare hands, electrocution is possible if the voltage difference has the potential to cause a lethal electric shock and the insulation on the conductors is insufficient to limit the current to below the threshold for a lethal electric shock.
oh okay, bats die when they hang on the cables, but they do not
provide any connection between live and ground, how is this possible?
Regarding your above comment to Solar Mike, it is ONLY possible for the bat to be electrocuted if the bat is simultaneously in contact with the high voltage wire and another wire or grounded object where the voltage between them has the potential to cause a lethal electric shock.
Bats are physically different than the typical birds you observe on HV wires. For one I understand they may have wingspans much larger than ordinary birds. So if they are on a HV wire and spread their wings, there is a higher likelihood that their wings will simultaneously contact more than one HV wire at a time, or some grounded part, causing lethal electric shock. Regardless of the reason for their deaths, they must simultaneously be in contact with two conductors with a potential difference capable of causing a lethal electric shock.
Hope this helps
The following is multiple choice question (with options) to answer.
F field mouse touched a special type of fence made for cattle and was killed instantly. The fence had a source of power. What happened? | [
"The mouse was frightened to death",
"The mouse had a heart attack",
"The mouse was electrocuted",
"The mouse had cancer"
] | C | electrocution causes harm to an organism |
OpenBookQA | OpenBookQA-1969 | c#, performance
-- EDIT : added detail about my gut feeling on necessity of balancement on evenly distributed number generator.
As stated in the comment i think that a plain selection (like the first one) is all you need. I think that the balancement proposed does not change probabiliry in a signifcant way.
Here my "gut feeling proof" :
if there is no balancement at all the, probability for pieces in a row are :
25%
6%
1%
0.3% (negletable)
With the current balancement :
25%
3%
0.3% (negletable)
The following is multiple choice question (with options) to answer.
A thing needs to be placed on a balance in order to determine | [
"hunger",
"shape",
"pressure",
"age"
] | C | a balance is used for measuring weight of a substance |
OpenBookQA | OpenBookQA-1970 | inorganic-chemistry, ions
Once you added a proton to the neutral ammonia molecule, you disturbed that original charge balance. There is a shortage of a single electron in the new molecule so formed and this denoted by the plus sign on the ammonium ion.
The following is multiple choice question (with options) to answer.
A chemical reaction may occur when _____ is added to an object. | [
"interest",
"warmth",
"puppies",
"loss"
] | B | adding heat to an object sometimes causes chemical reactions |
OpenBookQA | OpenBookQA-1971 | rotation, habitable-zone, weather, astrobiology
One of the interesting historical facts of life on Earth, at least to me, is how long it took what we might consider advanced life to develop. One celled life in various forms was around for over 3 billion years but the first fossils are about 650 million years old. It took life a very long time on earth to get from too small to see to large enough to leave a footprint . . . but, I digress.
I agree 100%, one celled life or Tardegrades could live on a planet with no tilt or 90 degree tilt. Easy. Ocean life in general should be fine cause oceans are more adaptive. Evaporation keeps ocean surfaces colder than land gets during peak heat and while a completely frozen over ocean isn't great for life, cold oceans hold more oxygen and CO2 which can be good for life. Oceans also circulate as an effective means of temperature moderation and fish don't really care how windy it is or how much or little it rains. The tilt question, I think, is really just about life on land.
Land life could be more vulnerable to high wind, extreme temperature shifts, droughts or floods, which could be driven by greater axial tilt, but I find it hard to believe that Axial Tilt is the be-all and end all. Day length and year length are key factors too.
One point I agree with the article on, is that a close to 90 degree tilt might not be ideal with one part of the planet always facing the sun and the other part never facing it but outside of extreme tilts, I don't see why it would be a big deal.
A thick cloud cover, for example, reduces seasonal changes. There's a number of factors.
The following is multiple choice question (with options) to answer.
If a person is lost in an arid space with little rainfall, they can live longer if they | [
"use water barely",
"use water freely",
"use water liberally",
"use water gratefully"
] | A | conserving water can be used for survival in a dry environment |
OpenBookQA | OpenBookQA-1972 | species-identification, ichthyology, limnology, aquatic-biology, freshwater-biology
Title: What kind of fish is this? Spotted or largemouth? I don't know if this is a weird looking largemouth bass or a spotted bass. It was caught in southern Oklahoma. Please help! Thanks. This looks like a spotted bass (Micropterus punctulatus).
Here's an image showing some quick differences between some common bass species:
Using the above photo and this source to guide our judgment we can see your specimen appears to:
Have a jaw that does not go posterior to the eye (as it otherwise would in a largemouth).
Have rows of pigment towards its ventral side (below the "lateral line").
Not have the typical darker horizontal line of scales characteristic of the largemouth bass .
Have smaller-sized cranial scales (those around the eye) characteristic of the spotted bass.
If you can provide additional pictures of the following, I can provide a more definitive ID:
Both dorsal fins -- if the 2 dorsal fins are connected, it would further suggest a spotted bass (as largemouth bass dorsal fins are not typically connected)
Tongue -- evidence of a tooth patch is more likely on the spotted bass.
According to the International Game Fish Association:
Spotted bass can be found throughout the central and lower Mississippi basin to the Gulf of Mexico (from Texas to the Florida panhandle), including Georgia, Alabama, Tennessee, Kentucky and other nearby states where it occurs naturally or has been introduced.
The following is multiple choice question (with options) to answer.
A bass may make its home | [
"in a liquid",
"in a field",
"in a tree",
"in a cage"
] | A | living things live in their habitat |
OpenBookQA | OpenBookQA-1973 | newtonian-mechanics, estimation
Would the rock have created a seismic event of its own (if so, how large)?
Would the rock have created a crater? The energy of the rock at the time of hitting the earth is mgh.
No rock we know of is going to be able to survive this collision with out breaking into pieces.
Non the less it will be a big impact and depending on the geology of the location it hits a variety of reactions scenarios can happen.
If the soil is aggregate of silt and sand and gravel, it would part into several shear rupture sections which look like slices of shell pattern surfaces starting from the bottom surface of the rock and turning up exiting the earth surface a few hundred yards outside of the impact zone and probably even eject some material out like a bomb crater. This scenario will have shakes that could be recorded miles away.
The calculation of how much of the momentum of rock will be shared with the shear material and accelerating them will be involved but not impossible.
If the geology of the impact area is of very low bearing like mostly silt and loose clays, the rock my lose most of its kinetic energy by just sinking into the dirt mostly with a giant humph with a cloud of dust rising.
If the geology is hard or rocky with the 'optimal' amount of mass and resilience it could create a substantial earthquake by resonating with the impact.
The following is multiple choice question (with options) to answer.
Sedimentary rock may be a result of | [
"metal",
"old silt",
"grass",
"hay"
] | B | nearly all fossils are found in sedimentary rock |
OpenBookQA | OpenBookQA-1974 | planetary-science, exoplanet
Since the planet hosted the first Foundation it is clearly habitable (i.e. atmosphere, no extreme temperatures). However, I am wondering how could it have so little metals if it seems so similar to Earth (habitability-wise) which has lots of metals. Is this possible in our Universe?
I am interested in answers that use current discovered exoplanets information or some articles that deal with planets come to be.
Question: Is it plausible for a planet that is positioned in the habitable area of a solar system to have little extractable metals? I'm going to approach this question in two steps: what metals are you talking about, and could you have a planet where those metals are not easily extractable.
What metals?
I get the sense that you're specifically referring to the non-lithophile metals, which include the d-block transition metals iron, nickel, copper and gold, and the chalcophile metals zinc, tin, lead, arsenic, mercury and silver.
This is an important distinction, since the advent of metallurgy was a critical step in human development in taking us out of the Stone Age, and it might be reasonable to posit that any advanced civilisation would follow a similar trajectory.
The final phase of the Stone Age, as we transitioned from the Neolithic to the Bronze Age, is called the Chalcolithic because it's marked by the first use of copper (although lead-smelting may have slightly preceded copper-working in some places). The Bronze Age initially alloyed copper with arsenic, but bronze made from copper and tin turned out to be both less toxic and more durable; bronze, in turn, was replaced by superior steel tools. Steel requires a sophisticated ferrous metallurgy involving iron alloys with a carbon content, and knowing how to make it is the mark of a culture's entry into the Iron Age.
[NB: There are plenty of iron relics that predate the Iron Age, but these were made from meteoric iron, an iron-nickel alloy that requires no prior smelting of ores; terrestrial iron's high melting point is well beyond the temperatures that could be achieved in Stone Age pottery kilns.]
Easily extractable?
Wikipedia describes the early stage of the Earth's formation:
The following is multiple choice question (with options) to answer.
Unlike trees in the forest or a pond full of fish, metal is only available until | [
"it is depleted for good",
"it is found on catfish scales",
"it becomes necessary to conduct electricity long distances",
"it is used to make diamond rings"
] | A | metal is a nonrenewable resource |
OpenBookQA | OpenBookQA-1975 | evolution, zoology
Let's say the environmental challenge for two different kinds of carnivore (let's call them Bogs and Dats) is to catch Mophers. Both Bogs and Dats initially have the same medium-to-short muzzles. Some Bog individuals figure out that they can dig Mophers out of their burrows, and some Dat individuals figure out that they can catch Mophers at night when the Mophers leave their burrows. Both strategies are successful. Some Bogs happen to have longer muzzles than their cousins, and find it turns out that longer muzzles work synergistically with the digging strategy, allowing Bogs to stick their noses into the Mopher burrows to grab escaping Mophers. The resulting fitness advantage results in an increase of the long-muzzle trait in further generations of Bogs. Note that in this scenario it is the adaptive behavioral strategy that creates selective pressure that favors a particular genetic adaptation.
Dats on the other hand, because of their nocturnal hunting strategy, benefit from improved night vision; and long muzzles don't provide any fitness advantage to Dats because Dats don't dig Mophers from their burrows. As long as Bogs and Dats don't hybridize, they will most likely end up with long and short muzzles respectively.
The Waddington effect, also called “Genetic Assimilation”, is somewhat more direct:
An environmental stress causes a proportion of a population to develop one or more abnormal traits, by interfering with embryological development.
If there is a selective pressure in the environment that favors some subset of those traits, individuals whose genetic makeup makes them more likely to develop that subset of traits, those individuals are likely to produce more descendants than other members of the population.
If being “more likely to develop” that subset of traits results from a weakening of genetically determined development controls that would otherwise prevent development of that subset of traits, then the subset of traits can eventually become the normal phenotype.
The following is multiple choice question (with options) to answer.
The quickness of this animal is a key change that allows it to escape attacks from feasting animals: | [
"the praying mantis",
"the potato bug",
"antelope",
"the eagle"
] | C | adaptations are used for survival |
OpenBookQA | OpenBookQA-1976 | species-identification, botany, ecology, trees
Title: Identifying a shrub with unusual "many shoots" growth behavior While recently hiking in the southern mountains of New Hampshire, we came across a plant, and some of them were exhibiting what we interpreted to be a disease, or least unusual growth. On some of the nodes, there were a large number of extra stalks:
On each plant, the number and locations of these things varied, and not all of them had it. And we first assumed it was some ivy, or parasite, or separate plant, but it seemed pretty clear to us that it was coming right from the same branch.
We soon saw there were dead versions of this plant, and all of them had this "extra shoot" variation:
So we reasoned that no matter what this thing was -- natural variation or some kind of disease -- it was killing the plants.
Google image search was no help. It possibly identified the plant as a "viburnum", but was unable to help with the growth.
Anyone know what plant this is, or what this growth behavior is the result of? Possibly an example of a "Witch's Broom."
Witch's Broom is a deformity in plants (typically woody species) which typically causes dense patches of stems/shoots to grow from a single point on the plant. The name comes from the broom-like appearance of the stems.1
Witch's broom may be caused by many different types of organisms, including fungi, oomycetes, insects, mistletoe, dwarf mistletoes, mites, nematodes, phytoplasmas, or viruses.2
Sources:
1. Wikipedia
2. Book of the British Countryside. Pub. London : Drive Publications, (1973). p. 519
Image1. Gardeningknowhow.com
Image2. Iowa state University
The following is multiple choice question (with options) to answer.
A rose bush photosynthesizes and nearby people | [
"are stung by bees",
"visit a foreign country",
"get new fresh air",
"drink more iced tea"
] | C | In the photosynthesis process oxygen has the role of waste product |
OpenBookQA | OpenBookQA-1977 | = ",Count[Drop[branches,gen],_Real,\[Infinity]]/4" "" ""Length = ",SetAccuracy[Count[Drop[branches,gen],_Real,\[Infinity]]/4*(Norm[{{pt1[[1]],0.5},{0,0}}]^gen),3]}],18],Gray],{2.3,-1.8}]},{Inset[Style[Text@TraditionalForm@Style[Row[{"Polynomial Trees by Bernat Espigulé"}],18],Gray, Opacity[0.4]],{2.3,-2}]}},PlotRange->{{-1.7,3.7},{-2.1,1.5}},ImageSize->{1000,600},Background->Black]],{{th,0.025,"Thickness"},0.005,0.185},{{gen,12,"Generations"},Range[1,16], ControlType -> SetterBar},{{pt1,{0.5,0.5}},{-0.5,0.5},{0.5,0.5},Locator}]Jurassic Trees
The following is multiple choice question (with options) to answer.
A tree is dead | [
"when a raccoon scurries up it's trunk",
"when a beaver uses it to a stop up a flowing river",
"when a possum hides in its branches",
"when an owl lives in it"
] | B | if a tree falls then that tree is dead |
OpenBookQA | OpenBookQA-1978 | human-anatomy
Taken from here such people would be able to dislocate then get their hands in front and relocate.
The body can be trained to be quite flexible through training like gymnastics etc...
The following is multiple choice question (with options) to answer.
A dead body will become what if exposed to the air | [
"hot remains",
"fresh remains",
"wet remains",
"skeletal remains"
] | D | In the food chain process bacteria have the role of decomposer |
OpenBookQA | OpenBookQA-1979 | taxonomy, mammals, cladistics
Title: Why aren't mammals and reptiles considered amphibians? We've all heard it: birds descend from dinosaurs, so they're dinosaurs too. But this got me thinking: doesn't this mean that, for instance, all terrestrial vertebrates – including humans – are technically fish? A recent video by MinuteEarth and the Wikipedia article for "Fish" confirmed my shower thought hypothesis.
Interesting. But... all amniotes, i.e. reptiles (and, by extension, birds) and mammals, descend from amphibians, right? If so, then why aren't they considered amphibians too? Mammals and reptiles aren't considered amphibians, because amniotes are not hypothesized to descend from Amphibia. That is to say that Amphibia did not evolve into Amniota. They are sister clades (actually Reptiliomorpha in the Tree of Life tree below).
The following is multiple choice question (with options) to answer.
Reptiles may actually be | [
"grumpy",
"brainless",
"magical",
"pea brained"
] | D | reptiles lay eggs |
OpenBookQA | OpenBookQA-1980 | biochemistry, metabolism, bioenergetics
Title: What is the energy source for adipocytes? Since adipocytes export fatty acids and glycerol and don't use them as an energy source, what is the main source of energy for adipocytes? Adipocytes use glucose as an energy source. They express the insulin-responsive glucose transporter GLUT4 just like muscle cells so that when blood glucose levels rise they are primed to take the glucose up for fatty acid biosynthesis, but they also use glucose as a fuel molecule.
The following is multiple choice question (with options) to answer.
What is a source of energy for animals? | [
"grains",
"air",
"space",
"sunlight"
] | A | food is a source of energy for animals |
OpenBookQA | OpenBookQA-1981 | python
def listen():
global loop_int, last_track
threading.Timer(loop_int, listen).start()
if it.player_state() == k.playing:
# check to see if track was restarted
if it.player_position() < getSec(it.current_track.time())/2 and last_track == it.current_track.persistent_ID():
self.last_track = '0'
# has the track played beyond the halfway mark?
if it.player_position() >= getSec(it.current_track.time())/2 and last_track != it.current_track.persistent_ID():
today = datetime.datetime.today()
now = '{}-{}-{} {}:{}:{}'.format(today.year, '%02d' % today.month, '%02d' % today.day, '%02d' % today.hour, '%02d' % today.minute, '%02d' % today.second)
print '\nArtist: {}\nTrack: {}\nAlbum: {}\nGenres: {}\nDatetime: {}'.format(it.current_track.artist().encode('ascii','ignore'), it.current_track.name().encode('ascii','ignore'), it.current_track.album().encode('ascii','ignore'), it.current_track.genre().encode('ascii','ignore'), now)
last_track = it.current_track.persistent_ID()
addTrack(it.current_track.persistent_ID(), it.current_track.name(), it.current_track.artist(), it.current_track.album(), it.current_track.genre(), it.current_track.played_count(), it.current_track.skipped_count(), it.current_track.year(), now, it.current_track.rating())
The following is multiple choice question (with options) to answer.
When a song is played your ears can | [
"change the source",
"rearrange the pitch",
"hum the tune",
"perceive the rhythm"
] | D | when sound reaches the ear , that sound can be heard |
OpenBookQA | OpenBookQA-1982 | genetics, mouse
Some researchers estimate that as many as 95% of CKCSs may have Chiari-like malformation (CM or CLM), the skull bone malformation believed to be a part of the cause of syringomyelia, and that more than 50% of cavaliers may have SM.* It is worldwide in scope and not limited to any country, breeding line, or kennel, and experts report that it is believed to be inherited in the cavalier King Charles spaniel. CM is so widespread in the cavalier that it may be an inherent part of the CKCS's breed standard.
(emphasis mine)
Same thing for that spine malformation that's related to selecting for corkscrew tails. The genes that make the tail corkscrew also mess with the spine.
In other words, the issue isn't inbreeding or not but whether the genes themselves are harmful. When organisms are selected for traits that are directly harmful in their extreme, or are associated with harmful genes that just happen to be next to those that are selected for in the chromosome, then the harmful consequences will spread through the population. Inbreeding is only a problem insofar as it allows the process go faster (more offspring per generation have the desired trait). On the other hand when you're just inbreeding with no specific focus on phenotype, or not phenotypes that have obvious harm associated (i.e. no lab would select for a frivolous trait that also causes harm. They're either selecting for the harmful trait on purpose, or they're selecting against it, because they'll want animals that are as healthy as possible except for the one variable they're interested in), then you'll end up with populations that are fairly normal except for some of the direct consequences of genetic uniformity.
It should be noted that most purebred dogs probably aren't inbred strains the same way many laboratory animals are; those are genetically identical, so the whole point is that their offspring will be like they are. So while they may be less fit than a non-inbred version of them might be, their offspring won't be any less fit than they are. And this is not what's observed with purebred animals like dogs and horses; individuals aren't identical, and looking at the page on Syringomyelia it seems the problems are getting worse.
The following is multiple choice question (with options) to answer.
Certain countries make it illegal to bring in certain species of animals that breed very fast because that will lead to | [
"extinction",
"milk",
"underpopulation",
"overpopulation"
] | D | if the population of an organism increases then the ecosystem may become overpopulated with that organism |
OpenBookQA | OpenBookQA-1983 | thermodynamics, energy, temperature, estimation
Title: What would happen if a 10-kg cube of iron, at a temperature close to 0 kelvin, suddenly appeared in your living room? What would be the effect of placing an object that cold in an environment that warm? Would the room just get a little colder? Would it kill everyone in the room like some kind of cold bomb? What would happen?
Don't think about how the cube got there, or the air which it would displace. Nothing overly dramatic, though it would be cool to look at. The cube would very quickly become covered by a layer of nitrogen/oxygen ice as the air which came into contact with it froze. Further away, you'd see condensation of water vapor into wispy clouds, which would swirl around the block due to the air currents generated by the sudden pressure drop.
Other than that, as long as you aren't in immediate thermal contact with the block, you wouldn't notice much other than that the room cools down. Here's a video I took of a vacuum can that was just removed from a dewar of liquid helium at 4 kelvin. It's maybe 5 kg of copper, not 10 kg of lead, but I'd say that's close enough to get the idea.
You can see one of my coworkers climbing down into a pit below it; he had to be careful not to bump his head on it, which would have really ruined his day, but there was no fatal cold bomb :)
The following is multiple choice question (with options) to answer.
An object inside a freezer will become less excited with energy an therefore become | [
"cold",
"round",
"warm",
"nervous"
] | A | something in a cold place becomes cold |
OpenBookQA | OpenBookQA-1984 | thermodynamics, heat, water, evaporation
Evaporating water does require heat, which comes primarily from the hot stones. So throwing water on the stones does cool them down.
(This is where the claim one occasionally hears, that "throwing water on the stones makes the sauna colder", comes from. Technically it's true, if one considers the total heat content of the sauna as a whole. But since most of that heat is in the stones, and since you don't sit on the stones, that's pretty much completely irrelevant to how hot the part of the sauna that you do sit in gets, or feels.)
On the other hand, throwing water on the stones also significantly increases the heat transfer rate from the stones to the air: the evaporation produces a lot of hot steam, which will rise and mix with the ambient air in the sauna. So it is possible for the air temperature in the sauna to increase, even as the stones are cooled down.
Also, the introduction of steam obviously increases the humidity of the air, which will increase the rate of water precipitation on skin, and/or decrease the rate of sweat evaporation. (The relative importance of these two effects will depend on the baseline humidity of the air, which can vary quite a lot. My gut feeling, based on experience, is that in all but the driest of saunas condensation probably dominates, simply because human skin is so much cooler than the air.) In either case, the effect will be to transfer more heat to the skin, and thus to make the air feel hotter.
Finally, as the hot steam rises off the stones, it will push hot air around the sauna in front of it. While this increase in air movement is slight and transient, it probably does have a noticeable effect: as the hot air flows past the people in the sauna, it will act to disperse the layer of cooler air that forms over the skin, and thus increases heat transfer to the skin. (If you don't believe me, try blowing some air over your skin in a sufficiently hot sauna. It burns.)
The following is multiple choice question (with options) to answer.
Perspiration leaving the torso through evaporation helps | [
"quench it's thirst",
"heat it up",
"cool it down",
"wash it off"
] | C | sweat cools a body |
OpenBookQA | OpenBookQA-1985 | zoology, mathematical-models, software, imaging
Title: What would it take to recognize a deer by its photo? I am trying to recognize a deer by its antlers or any other means.
Elaborating:
I was hoping to use their antlers to recognize them but I have heard that most deers shed their antlers every year so it would be difficult to recognize it from the last year's photo unless these antlers retain the same pattern every year.
If not the antlers, what other characteristics should I be looking for?
Is there any software that can help me in recognizing a deer? There is a lot of variation in how and when deer shed their antlers. In most arctic and temperate-zone species, antler growth and shedding is annual, and is controlled by the length of daylight. In tropical species, antlers may be shed at any time of year, and in some species such as the sambar, antlers last several years. Some equatorial deer never shed their antlers.
The horns change every year and, especially, increase the number of branches (and consequently, change their shape). You can't recognize them by antlers, but by other features, such as color of the hair or the lineaments. Like us, animals have individual morphological differences that are recognizable and listable.
Biologists specializing in studies of particular animal species not only take photos, but also make drawings and write descriptions of behavior, to identify individuals within herds.
An optical examination, however, of the subject through drawings and photos (and if possible, direct observation), is more useful than a PC program. This involves identifying particular similarities and equalities that are not "identical". This is possible to do visually on a large (but limited) number of specimens. The human eye is the best computer.
The following is multiple choice question (with options) to answer.
A type of animal that can shed is a | [
"frog",
"monkey",
"chicken",
"salmon"
] | B | shedding is when an animal loses hair |
OpenBookQA | OpenBookQA-1986 | inorganic-chemistry, extraction
I want to use household vinegar - 6% apple vinegar if possible because it is easily available. Also, I want to use 3% pharmacy grade $\ce{H2O2}$ for the same reasons.
I have done this, kind of successfully, but I want to know what is the chemistry behind all that, and how would you calculate the amounts of reagents needed? If you want to save the iodine $\ce{I_2}$ from its solution, you may add enough $\ce{KOH}$ or $\ce{NaOH}$ in the mixture to transform all $\ce{I_2}$ into a colorless mixture of $\ce{KI}$ and $\ce{KIO_3}$. $$\ce{3I_2 + 6OH^- -> IO_3^- + 5I^- + 3H_2O}$$The remaining ethanol can then be evaporated by heating the nearly colorless solution to a temperature higher than $80$°C. When the temperature reaches $100$°C, the ethanol is totally removed from the solution : the hot solution can be cooled down to room temperature, and some acid should be added in order to destroy the excess of $\ce{NaOH}$ ou $\ce{KOH}$, and then to recover the iodine $\ce{I_2}$ according to $$\ce{IO_3^- + 5 I^- + 6 H^+ -> 3 I_2 + 3 H_2O}$$ The totality of the iodine $\ce{I_2}$ dissolved in the original tincture is recovered, without any amount of ethanol, and can be saved by filtration.
The following is multiple choice question (with options) to answer.
A boy puts some vinegar in a glass of some bleach and finds | [
"both are frozen",
"bother taste good",
"both are dry",
"both are adjusted"
] | D | combining two substances chemically causes chemical reactions |
OpenBookQA | OpenBookQA-1987 | homework, plant-physiology, plant-anatomy
and 'Vascular Plants = Winning! - Crash Course Biology #37'
https://youtu.be/h9oDTMXM7M8?t=373
[5] Osmosis (water compensating solutes) "In Da Club - Membranes & Transport: Crash Course Biology #5"
https://youtu.be/dPKvHrD1eS4?list=PL3EED4C1D684D3ADF&t=148
Ian (and dad <= all errors and approximations are his :) ).
The following is multiple choice question (with options) to answer.
Transpiration | [
"is a control method for fertilizer in roses",
"is a control mechanism for root growth in sunflowers",
"is a control mechanism for H20 in daffodils",
"is a control method for argon in peonies"
] | C | plants control the amount of water in their leaves through transpiration |
OpenBookQA | OpenBookQA-1988 | python, beginner, game, functional-programming, adventure-game
winter = '\n' + '''29 January 2029. It is five weeks into winter and the season shows no mercy. A drought happened for a majority of the last fall and it devastated
the food supply. As your community dives deeper into the winter, you realize that your supply will run out if consumption is not altered. You could do one of two options: reduce
consumption among civilians, or ignore the risk and take a chance([ALTER SUPPLY]X} {B[IGNORE RISK]).''' + '\n> '
alter_supply = '\n' + '''Your government is now seen as selfish. You took the risk to protect the important people and "do your best with the rest". You have suffered heavy
civilian losses but your army and government losses have been few. As a result, there is division and danger in the streets. Riots breaking out, murders, arson, all happening in
your community.''' + civil_great_decrease
ignore_risk = '\n' + '''Your community did better than expected during the period. That is until you ran out of food in early March. Now you rely solely on scavenging,
risking getting devoured by zombies in order to go another day. Half your community is either dead or lost with great amount of casualties from civilians and
non-civilians.''' + army_great_decrease
The following is multiple choice question (with options) to answer.
Someone who's starving can be saved with | [
"some water",
"apple stems",
"a dried leaf",
"a coconut"
] | D | an animal requires nutrients for survival |
OpenBookQA | OpenBookQA-1989 | thermodynamics, temperature
Case 2:Milk is added at the beginning of the experiment
The only change from case 1 would be that the initial temperature of the solution would now be $T_0 - \Delta T$ instead of $T_0$.
So the solution fot $T$ will be :$T(t) = T_{env} + (T_0 -\Delta T- T_{env}) e^{-k t}$
Therefore after time $\tau$ the temperature of the solution will be:
$T_2(\tau) = T_{env} + (T_0 -\Delta T- T_{env}) e^{-k t}$
So finally we have,$T_2(\tau)-T_1(\tau)=\Delta T (1-e^{-k t})$
Now for all $t>0$,$(1-e^{-k t})$ is always positive.
So $T_2(\tau)>T_1(\tau)$ always.
Moral of the story:"If you want hot tea,add milk in the beginning!"
Note:Here we assumed Newton's Law of Cooling was valid which was somewhat a simplistic assumption which may not be true in the real world.
The following is multiple choice question (with options) to answer.
A plastic bag is filled with milk and is placed in a chest. The chest has a device which takes all of the warm air away, so eventually, the milk will | [
"quake",
"be seared",
"be solid",
"melt"
] | C | freezing point means temperature below which a liquid freezes |
OpenBookQA | OpenBookQA-1990 | climate-change, climate
In this case, as it is an area that it is almost constantly cloudy with high humidity, temperature is varying just a little bit, and except the first day of the period, it seems that there is no relationship. In fact, on the second day there was a storm (I am living now at Singapore) and it is reflected in a quick change in temperature (both) and solar radiation.
Conclusion: It is not as simple as it seems.
Hope it helps!
The following is multiple choice question (with options) to answer.
Seasonal changes are made in response to changes in what? | [
"mentality",
"buildings",
"environment safety",
"locales"
] | D | seasonal changes are made in response to changes in the environment |
OpenBookQA | OpenBookQA-1991 | newtonian-mechanics, energy, everyday-life, biophysics
Title: Why does running spend more energy than walking? The study energy expenditure of walking and running concludes that running spends more energy than walking.
My understanding is that although running makes one feel more tired, that only indicates that the power was higher (since the time of displacement was shorter), but at the end of the day the total energy dispensed to move oneself forward by friction should be the same.
Given the study shows otherwise, what could be the flaw in my reasoning? The basic reason is that an ideal object does work in the physics sense, but a biological entity has so many, many, ways it doesn't behave like an ideal object.
One can estimate and calculate, but other answers attempt that. I'm just going to try and summarise some of these big not-ideal-object behaviours
The following is multiple choice question (with options) to answer.
If you are feeling cold, its a good idea to go for a run or even a brisk walk because as you move, your energy is turned into what? | [
"Dogs",
"warmth",
"icicles",
"money"
] | B | moving changes stored energy into motion and heat |
OpenBookQA | OpenBookQA-1992 | photosynthesis, respiration, ecosystem, decomposition
Maybe you should study the metabolic processes of plants and life in general to better understand this. All life consists of chemical reactions that build up structures; in order to build them up you need energy (because of the second law of thermodynamics), and all living things create that energy by breaking down complex molecules into simpler ones. (as such it would be more accurate to say that all life consists of chemical reactions that build up and break down various structures). You might be wondering "but what about the difference between autotrophs and heterotrophs I heard about"; the difference between those is where they get the complex molecules from in the first place. Autotrophs use a different source of energy to build them up while heterotrophs get them from their environment. As such, you can think of every living thing as being made of two kind of molecules: those that actually form their structure (in humans, the molecules that make up cell membranes, bones, muscles, etc) and those that are stored in order to be broken down to power the whole system (in humans that's fat, glycogen, glucose, etc). Of course a molecule can do both; if you're starving your body may start to break down structural molecules for power. There are many different ways of breaking down those big molecules for power; the most efficient one, that starts with a big chain of carbon atoms and cuts it down into individual CO2 molecules using O2 molecules, is called aerobic respiration (i.e. respiration that uses oxygen).
Because those complex molecules are required to power all life, autotrophs (the organisms that actually make them) are very important, and the processes they use to make them are very important too. The process that makes almost all of the molecules that power almost all life on earth is photosynthesis, which uses the energy from the sun to power a reaction that converts CO2 from the atmosphere into big carbon-based molecules we'll call carbohydrates. This is called "fixing carbon", since the carbon atom is the most important one; measuring how much photosynthesis is happening is another way of measuring how many carbon atoms move from being part of a CO2 molecule to being part of a plant.
The following is multiple choice question (with options) to answer.
All organism require food to satiate themselves, grow big and strong, and also | [
"heal",
"make money",
"have fun",
"cry"
] | A | an animal requires nutrients to grow and heal |
OpenBookQA | OpenBookQA-1993 | geology, mineralogy, minerals, weathering
To me, supergene has a specific meaning, it may be part of the weathering process in some locations, but weathering involves the breaking down of rocks due to: reactions with atmospheric gasses, water (usually rain), changes brought on by plants, bacteria wind and temperature.
My suggestion to use the term weathering or weathered.
The following is multiple choice question (with options) to answer.
A plant's roots break down rocks as the roots do what? | [
"decay",
"grow old",
"develop",
"dcerease"
] | C | a plant 's roots slowly break down rocks as the roots grow |
OpenBookQA | OpenBookQA-1994 | genetics, sex, genomes
Title: sex limited genome transmission In general, for dioecious species, a large portion of the genome passed from parents to offspring of both sexes - in mammals the X-chromosomes and autosomes are passed from a mother to both daughters and sons, and autosomes from the father to both sons and daughters. Only the small amount of genes present in the Y-chromosome and mitochondria are inherited solely within one sex.
Is there any species (not just mammals) where most, or even all, of the genome is inherited in a sex-specific trajectory? What is the most sex-limited genome known to researchers? In birds and reptiles females are the heterogametic sex with allosome configuration ZW. However it has been reported that a homogametic WW female boa was born by parthenogenesis. So it means that although W is shorter than Z, it can still support life. So I guess that ZW system in general exchanges more sex-limited genetic material than XY system.
Platypus has 5 pairs of sex chromosomes. See here. This can qualify as the top case of sex-limited transmission.
The following is multiple choice question (with options) to answer.
All female platypus' | [
"lay eggs",
"give live birth",
"reframe from reproduction",
"give live aid"
] | B | a mother births offspring |
OpenBookQA | OpenBookQA-1995 | entomology
Title: The death of Earthworm In rainy season when children sprinkle salt on earthworm ,it dies.But salt is not dangerous.We use it daily.Then why earthworm dies? It's because on the earth worm skin's special mucous. Acording to this article: Why do earthworms die when salt is sprinkled on them? the mucous makes moist to the worm's skin, which is vital for their survival. Moreover, the worms don't have a respiratory organs, like lungs, gills, etc. This means that Carbon Dioxide and other characterized as "dump" gases can not be exchanged with the Oxygen. But worms breath through their skin, with the help of these special mucous that are developed on its skin. If their skin dries out the result will be death, because the gas exchange will not last without the mucous help. Similarly, the circulatory system won't function, because its main role is to trade gasses with the cells via red blood cells.
What about salinity?
Salinity is a very important factor for the earthworms health, because high salinity destroy their valunable and sensitive skin and kills the mucous that in fact help the worm to "breathe". Low salt concentrations are very beneficial for the worm, because not only their mortarity level is increaced, there are size changes to the worm's body (noticeable bigger size).
Here are and some photos of a worm that its enviroment has low salinity and high salinity:
High salinity:
Low-to-medium salinity
Source: Why do earthworms die when salt is sprinkled on them?.
The following is multiple choice question (with options) to answer.
A deer is killed and the body is broken down by worms and bacteria. The deer's body is | [
"bigger",
"has less mass",
"invisible",
"the same shape"
] | B | breaking down an object changes that object 's shape and mass |
OpenBookQA | OpenBookQA-1996 | sun
Title: Is there an instance where the sun sets or rises partly, then return back? I am reading Longest Sunset from XKCD. At first, I've thought that he mentions these phenomena just for fun, but it turns out to me that it might happens, based on the level of somewhat seriousness that I perceive from his writing. He doesn't talk about that in detail.
For the sunset:
Sunset starts the instant the Sun touches the horizon, and ends when it disappears completely. If the Sun touches the horizon and then lifts back up, the sunset is disqualified.
I'm not sure if the sunset is disqualified is because it happens, but we don't count it, or because he's just making fun. But I can't prove that this cannot happen. The more we head to the poles, the shorter the night is. Ultimately there will be a point that the sun still sets, but not completely, right?
For the sunrise:
For the purposes of our question, this is not a sunset:
The phrase for our purposes strengthen my doubt that he is being serious. The logic is the same above.
But these two illustrations are in the series of other apparently amusing ones, which are the sun as the cell in division, or as the egg in hatching (if you read the book, you will see this effect stronger).
So, is there an instance where the sun sets or rises partly, then return back? Yes, such sunrises happens every year at the beginning and end of the polar nights at high latitudes. One can have a few days with a glimpse of the sun but disqualified sunsets and sunrises.
Sunsets occur at the end of the midnight sun period by the end of the summer, the first sunset is not complete.
Sun at it's highest elevation at midday. (To be honest, the picture might be taken the day after the first sunrise, as some mountains are hiding the horizon.)
Here is e.g. an article from Svalbardsposten, the northernmost newspaper in the world, reporting of the first rays of sunlight after the polar night and some pictures from the last sunrise/sunset before the polar night in northern Sweden.
The same occurs at the southern polar circle and south thereof, unless it's cloudy...
Update: here is a great time laps from Davis Station in the Vestfold Hills showing exactly what you asked about: Mid winter
The following is multiple choice question (with options) to answer.
The sun is good for | [
"Brownies",
"Envrionments",
"Buildings",
"Cars"
] | B | a planet is exposed to the heat of the star around which it revolves |
OpenBookQA | OpenBookQA-1997 | orbital-motion, solar-system, celestial-mechanics, chaos-theory
On predicting eclipses
The issue of chaos becomes even more extreme when trying to predict eclipses, particularly solar eclipses. The Sun, Jupiter, and Venus have marked effects on the long-term behavior of the Moon's orbit. Even more importantly, however, the Moon is receding from the Earth due to tidal interactions, and this rate is not constant. The current recession rate is about twice the average rate over the last several hundred million years. Changes in the shape and interconnectivity of the oceans drastically changes the rate at which the Moon recedes from the Earth. The melting of the ice covering Antarctica and Greenland would also significantly change the recession rate, as would the Earth entering another glaciation. Even a small change destroys the ability to make long term predictions of the Moon's orbit.
NASA developed a pair of catalogs of solar eclipses: one covering a 5,000-year period spanning from about 4000 years ago to about 1000 years into the future; the other a 10,000-year catalog of solar eclipses spanning from about 6000 years ago to about 4000 years into the future. The accuracy of these catalog degrades drastically before 3000 years ago and after 1000 years into the figure. Beyond these inner limits, the path of the eclipse over the Earth's surface becomes markedly unreliable, as does the ability to determine whether the eclipse will be partial, total, annular, or hybrid. At the outer time limits of the longer catalog, whether an eclipse did / will occur begins to become a bit dubious.
Because of the Earth's much larger shadow, predictions of lunar eclipses are a bit more reliable, but not much. The problem is that of exponential error growth, which is a characteristic of dynamically chaotic systems. Predictions of lunar eclipses more than a few tens of thousands of years into the future are more or less nonsense. The millions of years asked in the question: No.
The technique of orbital averaging once again can be of aid in determining characteristics of the Moon's orbit (but not position on the orbit). This can be augmented by geological records. Various tidal rhythmites give clues as to the paleological orbit of the Moon. A few rock formations exhibit layering that recorded the number of days in a month and the number of months in a year at the time the rock formation was created.
References
The following is multiple choice question (with options) to answer.
The lunar face appears to change 52 times | [
"a millennium",
"a month",
"a day",
"annually"
] | D | a different moon phase occurs once per week |
OpenBookQA | OpenBookQA-1998 | geophysics, earth-rotation, earth-system, solar-terrestrial-physics, time
(image from Wikipedia commons, originally here)
But as a consequence of these tiny variations, almost every year one or two (leap seconds) are added to our clocks to keep them aligned with the rotation of the Earth. In the long run (millennia), Earth days are getting longer (~0.017 milliseconds per year). Some of the factors involved were discussed in this question.
Finally to address whether changes in orbital speed affect rotational speed: I don't think so. For what I understand none of those small changes in the length of the day is a direct consequence of changes in the orbital speed. However, despite there is no changes in the speed of rotation, what we generally understand as a day (i.e. the time between two consecutive sunrises, sunsets or noon), is not only controlled by the rotation of the Earth around its axis. In fact, one out of the ~365 days of the year is consequence of Earth's revolution around the Sun, not its rotation. And that one-day contribution give rise to the difference between a day and a sidereal day, and the variations in the duration of the apparent solar day, variations that are directly controlled by Earth's orbital speed and can change the time between solar noon up to about 30 seconds over a year.
The following is multiple choice question (with options) to answer.
How many times does the Earth complete a revolution around the sun in a decade? | [
"twelve",
"one",
"ten",
"two"
] | C | a complete revolution of the Earth around the sun takes one solar year |
OpenBookQA | OpenBookQA-1999 | physical-chemistry, thermodynamics, gas-laws
Title: What will happen to the entropy and free energy of the gasses when the partition is removed?
Consider a container of volume $ 5.0$ L that is divided into two compartments of
equal size. In the left compartment there is nitrogen at $1.0$ $atm$ and $25 °C$; in the
right compartment there is hydrogen at the same temperature and pressure. What
will happen when the partition is removed?
$A) $The entropy decreases, and the free energy decreases.
$B)$ The entropy increases, and the free energy decreases.
$C) $The entropy increases, and the free energy increases.
$D) $The entropy decreases, and the free energy increases.
Logic tells that upon removing the partition, randomness increases and hence entropy increases. I am confused about free energy. First law of thermodynamics has to be applied , I think. But I can't seem to get the right direction. A Spontaneous process is characterized by an increase in the total entropy (for both system and surroundings).
Spontaneous processes are characterized by a decrease in free energy (analogous to the decrease in gravitational potential energy occurring for a ball rolling downhill).
The following is multiple choice question (with options) to answer.
What will happen to gas once heated? | [
"melting",
"freezing",
"ascension",
"cooling"
] | C | if gas is heated then that gas will rise |
OpenBookQA | OpenBookQA-2000 | zoology
Title: Can my dog really understand me? Are dogs capable to understands human language ( for example after order sit it sit because he know that word) Or can sence our order by body language and intonation if so why this type of communication developed only at dogs? Some researchers say that dogs have the intelligence of a two-year old.
Many dogs can understand more than 150 words and intentionally deceive other dogs and people to get treats, according to psychologist and leading canine researcher Stanley Coren, PhD, of the University of British Columbia.
He is a reasonable and serious scientist who is biased towards overstating dog intelligence. he sais:
The average dog can learn 165 words, including signals, and the “super dogs” (those in the top 20 percent of dog intelligence) can learn 250 words, Coren says. “The upper limit of dogs’ ability to learn language is partly based on a study of a border collie named Rico who showed knowledge of 200 spoken words and demonstrated ’fast-track learning,’ which scientists believed to be found only in humans and language learning apes,”
Dogs can also count up to four or five,
http://www.apa.org/news/press/releases/2009/08/dogs-think.aspx
The following is multiple choice question (with options) to answer.
If an animal is trained to do something, that is a learned what? | [
"mode of conduct",
"sensation",
"emotion",
"feeling"
] | A | if an animal is trained to do something then that something is a learned behavior |
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