source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-2701 | species-identification
Title: What species of viper is this? I think that the snake in the pictures here below is a viper. I found it on a hiking trail on a mountain in Bulgaria. Height was about 2000 meters and the weather wasn't warm as you might expect in a late Spring days, but it seemed quite active.
If it really is a viper what species of viper? Otherwise what could it be? This is most likely the common European adder (Vipera beris). A list of the reptiles of Bulgaria lists it as occurring in the mountains of Bulgaria up to 2700 metres.
There are a couple of other contenders in the list of vipers, but two of them are incredibly rare (not found since the 1930's) and the last is the horned viper (Vipera ammodytes), which has distinctive horns on the tip of its nose.
The following is multiple choice question (with options) to answer.
Where do grass snakes live? | [
"icebergs",
"a field",
"grass fed cattle",
"amphibians on Uranus"
] | B | grass snakes live in grass |
OpenBookQA | OpenBookQA-2702 | neuroscience
Title: Nervous system : Nerve signals If the electrical signals from all the various organs throughout the body eventually connect to the nerves in the spinal column traveling up to the brain, how does the brain differentiate the different signals. Is the nerve in the spinal column like an electrical conduit with many wires inside? Yes is the simple answer. A nerve will go up to a specific part of the brain which the brain knows corresponds to a certain region of the body. It isn't perfect though e.g. pain in the diaphragm confuses the brain which doesn't recognise that pain must be coming from there so instead tells the body there is shoulder pain, however this is useful in medicine. Another infamous example is pain from heart disease (angina) which causes pain in the jaw and arm. Perhaps even more interestingly, if a nerve is cut and then grows back linking to the wrong nerve it may lead to the completely wrong part of the body being identified when touched. Also if the brain itself is stimulated in these corresponding areas, a person will feel he or she is indeed being touched in a certain part of the body.
The following is multiple choice question (with options) to answer.
Which likely has an electrical conductor that sends sensation through an organism? | [
"rock",
"ice",
"shrew",
"tree"
] | C | nervous system is an electric conductor |
OpenBookQA | OpenBookQA-2703 | evolution, taxonomy, ornithology
Title: Birds and Dinosaurs This came up in an argument with some friends. I know that birds are direct descendants of dinosaurs, shown pretty clearly through the fossil record. However, is it proper to say that birds are dinosaurs, or is there an actual distinction? I bet you'll be interested about the concept monophyly. Any human-made group of species (or taxon) like birds dinosaurs, primate, bacteria, angiosperm, reptiles, … are either monophyletic, polyphyletic or paraphyletic. This picture explain the concept When the taxon is monophyletic it is called a clade.
Monophyletic taxon are those groups of species that can be considered to be objective in the sense that it represents a group of species where each species in the taxon is more related (in terms of time to common ancestor, not according to their genetic similarity) to any other species within the same taxon than to any other species outside this taxon. This is obviously not the case for paraphyletic or polyphyletic taxon.
Typically, we do not consider a parrot or a deer to be reptiles. Therefore, the ususal understanding of "reptiles" makes this taxon paraphyletic. Now, one should not confound the common understanding (what is a reptile in our everyday life) with the strict definition of the taxon Reptilia, which is a monophyletic taxon (or a clade in other words). Probably the best source for exploring the tree of life is tolweb.org. Here, you will find the clade Reptilia (who include birds, snakes, turtles and lizards). Note: Mammals are within the Reptiliomorpha, not the Reptilia.
It is exactly the same issue with the dinosaurs. When we talk about dinosaurs in our everyday life we do not mean birds. But there is a clade called Dinosauria, which include both dinosaurs and birds.
In short, I would say that a bird is a Dinosauria (monophyletic taxon) but is not a dinosaur (paraphyletic taxon). But this little play on word is not a scientific issue but an issue of english usage.
You will also find in this post an introduction to phylogeny
The following is multiple choice question (with options) to answer.
Dinosaur carcasses are a form of | [
"car parts",
"fuel",
"fun",
"food"
] | B | oil is a source of energy |
OpenBookQA | OpenBookQA-2704 | geophysics, seismology, instrumentation
Title: How can I calculate the sensitivity of a seismometer? I would like to know if a specific seismometer can measure 1 micron/sec velocity. I have a few specs from the datasheet but I'm not a seismologist and am trying to figure out how to relate the specs to one another.
I have:
Velocity output band: 30s (0.03Hz) to 100 Hz
Output Sensitivity: 2400 V/m/s
Peak/Full scale output: Differential: +- 20V
Sensor dynamic range: 137 dB @ 5 Hz
Thanks in advance! This is a partial answer because I'm not an expert and because I don't know what the dynamic range of 137 dB means. Hopefully you can add a little more information.
tl;dr: if 137 dB is the dynamic range in power, then it's 68.5 dB in voltage and velocity which sounds more plausible, and makes the velocity sensitivity well below 1 micron per second. However we don't yet know what the noise and bandwidth of your signal are yet so we can't evaluate that.
I have a few specs from the datasheet...
The more information you share from the data sheet the better although I've now just noticed that the question is about three years old.
Also, there may be some helpful insight at How sensitive are typical seismometers?
The following is multiple choice question (with options) to answer.
A seismometer will be able to tell how much this was quaking: | [
"tree",
"bird",
"shoe",
"bed"
] | A | a seismometer is used to measure the strength or magnitude of an earthquake |
OpenBookQA | OpenBookQA-2705 | zoology, ecology, species-distribution, migration
Title: How do animals end up in remote areas? I was thinking specifically about random marshy water holes on farmers fields. It seems that you can visit just about any one of these and you will find frogs if you look hard enough.
They usually don't seem to be connected to each other. If it were any other land animal I would figure they walk from one spot to another, but in the case of frogs, I don't imagine their range is very vast. But often these marshy spots can be separated by fairly large distances to a frog.
So this brings me to my question: how do each of these spots end up with frogs in them? I don't imagine a frog is going to go hopping over a hill to get to a marsh on the other side, is it? This question pertains to organism dispersal, which is a very active field of study with relation to it's impact on conservation efforts. Much of what I will say below has been covered in this wiki.
Definition: From the Wiki
Technically, dispersal is defined as any movement that has the
potential to lead to gene flow.
It can be broadly classified into two categories:
Density dependent dispersal
Density independent dispersal
The question of frogs and fishes both refer to Density independent dispersal, while an example of density independent dispersal can be the competition for habitat space between big cats and humans (this is a WWF pdf)
From the wiki:
Density-independent dispersal
Organisms have evolved adaptations for dispersal that take advantage
of various forms of kinetic energy occurring naturally in the
environment. This is referred to as density independent or passive
dispersal and operates on many groups of organisms (some
invertebrates, fish, insects and sessile organisms such as plants)
that depend on animal vectors, wind, gravity or current for dispersal.
Density-dependent dispersal
Density dependent or active dispersal for many animals largely depends
on factors such as local population size, resource competition,
habitat quality, and habitat size.
Currently, some studies suggest the same.
This study in particular studied the movement and habitat occupancy patterns within ephemeral and permanent water bodies in response to flooding. They found that during flooding these frogs moved out to flooded ephemeral water bodies and later on moved back again to the permanent ones.
Other suggested readings for those highly interested in the subject may include this (a phd thesis) and this (a project report)
The following is multiple choice question (with options) to answer.
migration is when animals travel from the north to Texas during what segment of time? | [
"beach area",
"spring",
"winter",
"birds"
] | C | some birds live in forests |
OpenBookQA | OpenBookQA-2706 | newtonian-mechanics, forces, conservation-laws, collision, free-body-diagram
So, we've just demonstrated that the ground can and does produce a greater force on the object than its weight. If this effect continues after the object's velocity reaches zero, then the object will rebound (i.e. it is an elastic collision). On the other hand, if the force reduces to the object's weight once it reaches zero velocity, the object will stop at the ground (i.e. an inelastic collision).
There are other, more elaborate, and more robust ways of looking at the problem. As we say in physics, "there's more than one way to do it." However, this is the answer using only Newton's Laws, and there is no need to make the answer more elaborate than it needs to be.
The following is multiple choice question (with options) to answer.
An object that is stopped is | [
"accelerated",
"halted",
"off-balance.",
"wind-blown"
] | B | stopped means no speed |
OpenBookQA | OpenBookQA-2707 | 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.
If a leg is moving then the bones inside the skin are | [
"being controlled by brawn",
"being slowly softened up",
"being made to break down",
"being torn into pieces"
] | A | muscles pull bones to move the bones |
OpenBookQA | OpenBookQA-2708 | fluid-dynamics, everyday-life, water
As can be seen from these photos, the colour dye is present in the water jets which recoil off the surface of the transparent pool water. However, not all of the water in the jets is from the coloured drop. Some of the original drop is trapped in a pocket below the surface, with the rebounding 'jets' having a 'coating' of the original drop material. The way we know this is because in the experiment, the coloured drop was made from water mixed with thymol blue, an indicator which is dark orange in colour at neutral-to-acidic pH. The pool water contained 0.1% sodium carbonate (alkali), which is transparent in colour, but when the two combined, the mixture turns blue in colour.
Some fascinating insight into the phenomenon can be gained by examining some high speed video footage.
If you look at this high speed video, you will see that when the water droplet falls into the water, it appears to bounce back out!
An even better example of the 'bouncing' phenonenon can be found in this video, when the drop is released gently from close to the surface of the water, it appears that after the drop is 'coalesced' into the water, part of it 'bounces' back out as a smaller droplet, which the falls back and floats on the surface of the water.
The explanation offered is that a layer of air gets trapped beneath the droplet as it hits the surface of the water. Some of the water in the droplet gets coalesced into the pool by the water tension, releasing a smaller droplet back out.
The following is multiple choice question (with options) to answer.
In an experiment, chemical splashing can happen so | [
"be dangerous",
"be safe",
"be messy",
"be playful"
] | B | chemical splashing sometimes occurs during experiments |
OpenBookQA | OpenBookQA-2709 | career
Title: Data science career problems: interaction of technical and social difficulties I have been trying to break into the bioinformatics space (and now, data science more generally).
Although there are numerous challenges in this field and I am constantly learning to deal with them, I have have found the most consistent and intractible challenges are interpersonal, and they are unlike anything that my previous experience prepared me for. In particular, I find it very difficult to balance between getting the information I need (or think I need) to do a good analysis and maintaining productive relationships with people.
I have often had the sense that higher-ranking people than me were using their ability to act as gatekeepers of information to assert power over me, but it is almost never possible to be sure whether this is what is going on, or if I am making up excuses for my own lack of planning and follow-through.
A few examples.
The following is multiple choice question (with options) to answer.
A person who has a job of making discoveries also | [
"watches",
"fights",
"slaughters",
"explodes"
] | A | scientists make observations |
OpenBookQA | OpenBookQA-2710 | organic-chemistry, physical-chemistry, biochemistry, alcohols
Title: Storage of Urine Not all may be favorable to this project, but I will explain what I am trying to do. I work at home, and instead of walking a moderate distance to the bathroom and loosing my focus, I've been, at times, peeing in a 3 Quart Poland Springs water bottle. If you take offense at this, please do not continue reading except to be helpful in the scientific goal. I know this subject won't suit many types of people, so just ignore it if that is your case.
I noticed first of all that urine is not at all as sterile as people say that it is. The rate of growth of bacteria is relatively slow, but as a precaution, I found the need to use additional measures to prevent the growth of bacteria. I settled on the following method: I have two bottles and I add to each bottle about enough salt as can be soluble in the urine and sometimes maybe a little more. The one bottle then fills up throughout the day and is emptied, washed, and refilled with salt. The salt helps to kill the bacteria which would be lingering in the empty bottle. The next day, the bottle stays empty and the other is used.
I would add that I discovered that the bacteria (without the salt) does not usually grow unless the bottle is left with urine for two days. After this, however, that same bottle (without the salt) would retain the bacteria and immediately grow, if used again.
This system works relatively well, so long as it is done every day. It will even withstand 2 days with only moderate growth. (If I should leave it by mistake for longer it can get ugly). Nevertheless, I am still looking to improve upon this. One reason is that, if I drink less water or relieve myself normally, the bottle does not fill in one day. I am looking for someone with knowledge of chemistry to help me find a substance that can be added to this solution which fits a number of common sense criteria. I will also add a list of the substances that I have tried or already considered.
Necessary qualities
The following is multiple choice question (with options) to answer.
A way to conserve something is to | [
"use it up",
"use it sparsely",
"use it quickly",
"finish it off"
] | B | An example of conservation is not using fossil fuel |
OpenBookQA | OpenBookQA-2711 | # Word problem help
#### Stephen
could you please tell me how I set this up to solve? thanks
a veterinarian has two solutions that contain different concentrations of a certain medicine. One is 15% concentration and the other is 5 % concentration. How many cubic centimeters of each should the veterinarian mix to get 20 cc of a 6 % solution?
#### Grandad
MHF Hall of Honor
Hello Stephen
Welcome to Math Help Forum!
could you please tell me how I set this up to solve? thanks
a veterinarian has two solutions that contain different concentrations of a certain medicine. One is 15% concentration and the other is 5 % concentration. How many cubic centimeters of each should the veterinarian mix to get 20 cc of a 6 % solution?
Suppose he uses $$\displaystyle \displaystyle x$$ cc of the first solution, and $$\displaystyle \displaystyle y$$ cc of the second. Then we can set up two simultaneous equations as follows:
The total volume must be 20 cc. Therefore
$$\displaystyle \displaystyle x+y = ...$$ ?
This is equation (1).
The quantity of the medicine in $$\displaystyle \displaystyle x$$ cc of the first solution is $$\displaystyle \displaystyle \frac{15x}{100}$$.
The quantity of the medicine in $$\displaystyle \displaystyle y$$ cc of the second solution is $$\displaystyle \displaystyle \frac{5y}{100}$$.
The total quantity of medicine in the mixture is therefore ... ?
This must be 6% of the total volume, $$\displaystyle \displaystyle 20$$ cc, which is $$\displaystyle \displaystyle \frac{6\times 20}{100} = ...$$ ?
The second equation is therefore
$$\displaystyle \displaystyle \frac{15x}{100}+\frac{5y}{100}=...$$ ?
This is equation (2).
Can you complete what I have started, and then solve the simultaneous equations to find $$\displaystyle \displaystyle x$$ and $$\displaystyle \displaystyle y$$?
Grandad
#### Soroban
The following is multiple choice question (with options) to answer.
Kool-aid is a mix of what items as a solution? | [
"sugar candy from store",
"water fluid within a sugar casing",
"soda pop within a can",
"sweets grains and flavors dissolved in liquid base of water"
] | D | a solution is made of one substance dissolved in another substance |
OpenBookQA | OpenBookQA-2712 | # Thread: Most likely of two examples
1. ## Most likely of two examples
Hi My instructor gave us two examples and posed a question:
We have a fair coin which is more likely?
1. We flip the coin 100 times and see exactly 50 heads.
2. We flip the coin 1000 times and see exactly 500 heads.
Someone in the class said immediately that 1 is more likely by a factor of sqrt(10). Why is sqrt(10) the difference? Now explanation was given.
2. ## Re: Most likely of two examples
Hint: Try calculating the actual probability using the PDF (or by using a Normal distribution approximation with continuity correction).
Have you come across using the Normal distribution to approximate a binomial distribution for large values of n?
3. ## Re: Most likely of two examples
The binomial distribution with N= 100, p= 1/2 has mean 50 and standard deviation $\sqrt{(100)(1/2)(1/2)}= \sqrt{25}= 5$. To approximate that with the Normal distribution, use a normal distribution with that mean and standard deviation and find the probability that x is between 50- 1/2= 49.5 and 50+ 1/2= 50.5.
To do the same with N= 1000, p= 1/2, mean is 500 and standard deviation $\sqrt{1000}(1/2)(1/2)}= \sqrt{250}= 5\sqrt{10}$. Find the probability of x between 500- 1/2= 499.5 and 500+ 1/2= 500.5.
The following is multiple choice question (with options) to answer.
Which of the following is most likely to occur? | [
"an archaeologist finds an ancient crustacean in magma",
"an archaeologist finds an ancient crustacean in limestone",
"an archaeologist finds an ancient human in limestone",
"an archaeologist finds an ancient human in magma"
] | B | organisms can be preserved in sedimentary rock |
OpenBookQA | OpenBookQA-2713 | natural-disasters, forest, extreme-weather, fire
Title: Why don't forest fires in Western Australia get as much attention as forest fires in the southeast of the country (including SA)? WA gets plenty hot and dry in the summer (especially Exmouth and points south where Top End moisture isn't as prevalent), but I don't hear so much about catastrophic forest fires hitting WA, like I do about those that hit SA, VIC/TAS, NSW/ACT/SE QLD year in and year (it's events in these states that most often make international news), with the odd exception like the Perth bushfires of November 2011. Is there a meteorological or geological reason that the WA wildfire season can be forgotten as compared to wildfires in the eastern states of Australia? Forest fires, and natural disasters in general, get attention when they affect people.
Bush fires outside of metropolitan Perth or far away from populated areas do not affect many people. Therefore, media attention is diverted elsewhere. This is not unique to WA: you have the same in NT, northern SA, and the west of eastern states.
This is also not unique to bush fires. Volcanoes only get media attention when they affect people: recent examples are Fuego in Guatemala or Kilauea in Hawaii. The other 50 or so active volcanoes in 2018 get close to zero media attention, because they do not affect anyone (or at least, they do not affect people that the Western media cares about).
The following is multiple choice question (with options) to answer.
if a bush fire breaks out without human action, what might have happened? | [
"the mercury read high in the thermometer that day",
"it was a cloudy day",
"it was a very rainy day",
"it was a very cold day"
] | A | high temperatures can cause an object to combust |
OpenBookQA | OpenBookQA-2714 | Best Japanese Brown Rice, Air Fryer Burgers And Fries, østfold University College Vacancies, Band T-shirts Walmart, How To Become An Anglican Priest, Too Much Fennel Taste, Porter Cable Circular Saw Cordless, Utmb My Chart, Iams Large Breed Dog Food Nutrition Facts,
The following is multiple choice question (with options) to answer.
Which would likeliest eat a sardine? | [
"a plant",
"a tree",
"a canary",
"a tunafish"
] | D | tuna eat fish |
OpenBookQA | OpenBookQA-2715 | habitable-zone
An orange dwarf star may live for 10 to 30 billions years in the main sequence. A red dwarf star may live in the main sequence for trillions of years.
However, planets in the habitable zone of red dwarfs are likely to become tidally lock, and we don't know if this is really that bad or not for life biodiversity. Lets assume that this is really bad, so a planet orbiting an orange dwarf in the habitable zone is likely to have a better habitability than Earth.
Accordingly to this, a planet with two times the mass of the Earth, will have stronger gravity, and thus it is likely to be flatter. Further, it is likely to have a ticker atmosphere that would protect the surface from UV radiation better than Earth. It would be geologically active for a longer time, resulting in more carbon cycling. With the right quantity of water (not a desert nor a global very deep ocean), it might be an archipelago world, since its flatness would not allow the ocean to be very deep nor the continents to be very large. As a result, life would flourish in a number of rich biologically favourable environments significantly larger than Earth. Further it magnetic field is likely to be stronger than Earth's one, protecting the surface from cosmic rays.
As a result, a planet with two Earth masses orbiting an orange dwarf star in the habitable zone has a good chance to be more habitable to life than Earth itself.
Needless to say, near-circular orbits are more favourable than excentric ones, since excentric orbits may make the planet enter in periods of freezing or boiling. However, a reasonably excentricity that periodically changes the environment in a significant manner, but not as too much that it would extinguish non-extremophile life, might give to the planet life a selective pressure needed for developing rapid evolution to face the always changing climate.
The following is multiple choice question (with options) to answer.
Where would a polar bear enjoy living | [
"in a small cage",
"in a reef in the ocean",
"in a tropical environment",
"much closer to one of the earth's poles than to the equator"
] | D | polar bears live in cold environments |
OpenBookQA | OpenBookQA-2716 | astronomy, telescopes
Title: Fall/Winter Viewing I live in Seattle and am thinking of purchasing a telescope. Is fall/winter a decent time of year for viewing (aside from summer)? Are there any major viewings/events during that this of year?
I know I live in a city of rain, but there are some nice nights. The sky is a constantly changing tapestry of interesting sights and events: there is no time better than any other. If you''re interested, now is the best time!
Because of our location in the Milky Way Galaxy, summer and winter are the best times for viewing objects within the galaxy: open clusters and nebulae. Spring and fall are the best times to view objects outside our galaxy: globular clusters and other galaxies. Because of the Earth's rotation, if you stay up late, you can also get a sampling of the next season. Look at the autumn galaxies this evening, then stay up past midnight to view the winter clusters and nebulae.
Superimposed on the "deep sky" are the solar system objects, which operate on their own clock. Right now, Saturn is disappearing in the west at sunset but Venus will soon replace it; Jupiter rises around 10 p.m. and dominates the rest of the night. Mars is still far away in the morning sky, but is gradually getting closer.
The following is multiple choice question (with options) to answer.
If you wanted to see snow year round you would go to the | [
"new zealand",
"arctic",
"hawaii",
"beach"
] | B | the arctic environment is covered in snow |
OpenBookQA | OpenBookQA-2717 | space, rocket-science, space-travel
Title: Get into orbit from the Redbull jump position to a satellite position by using a cord/rope? Its difficult to put this into the title.
I was watching the Redbull Jump and noticed that the height of this is at 39 kilometres (24 mi) the atmosphere pressure is at I believe about 0.4% of that at sea-level. I was imagining, what if a large satellite dragged a cable (bungie cord, rope) below it into the atmosphere and the person grabbed onto the cord that is below the satellite, from the position of the Redbull jump altitude. The satellite may or may not be geo-stationary.
Since the atmosphere pressure is low, even if the cable was moving through the atmosphere, its air friction would be relatively low and therefore its movement through the atmosphere wouldn't be much of a concern. Maybe there would be a lower chance of the cable breaking, also less cable length and therefore less weight could be used.
Would this be a better way to get an object into space when compared with a full cable from the satellite to earth as in the traditional space elevator idea http://en.wikipedia.org/wiki/Space_elevator.
Can you compare and contrast the two options against each other?
Photo of Red Bull Jump
https://i.stack.imgur.com/3MRAe.jpg The practical lowest orbit is around 300km and a velocity of 8km/s - around 26 times the speed of sound at the altitude of the balloon jump.
So imagine the mass of a 300km long rope and even with a thin atmosphere there is quite a lot of friction on something moving at Mach 26
The following is multiple choice question (with options) to answer.
Where could you most likely jump to the top of a mountain? | [
"near the equator",
"on the moon",
"near the sea",
"in a laboratory"
] | B | the surface of the Moon contains mountains |
OpenBookQA | OpenBookQA-2718 | biochemistry, botany, plant-physiology, photosynthesis
What are typical characteristics of different plants in this regard? I.e., how do common species of plants manage their C consumption before (and after) the development of leaves? There are quite a few questions and thoughts in there, I'll try to cover them all:
First, to correct your initial word equation: During photosynthesis, a plant translates CO2 and water into O2 and carbon compounds using energy from light (photons).
You are correct to assume the C is further used for the growing process; it is used to make sugars which store energy in their bonds. That energy is then released when required to power other reactions, which is how a plant lives and grows. C is also incorporated into all the organic molecules in the plant.
Plants require several things to live: CO2, light, water and minerals. If any of those things is missing for a sustained period, growth will suffer. Most molecules in a plant require some carbon, which comes originally from CO2, and also an assortment of other elements which come from the mineral nutrients in the soil. So the plant is completely reliant on minerals.
Most plants, before a leaf is established or roots develop, grow using energy and nutrients stored in the endosperm and cotyledons of the seed. I whipped up a rough diagram below. Cotyledons are primitive leaves inside the seed. The endosperm is a starchy tissue used only for storage of nutrients and energy. The radicle is the juvenile root. The embryo is the baby plant.
The following is multiple choice question (with options) to answer.
What requires photosynthesis to grow? | [
"sunlight",
"local flora",
"power plants",
"plant toys"
] | B | a plant requires photosynthesis to grow |
OpenBookQA | OpenBookQA-2719 | botany
Title: Do plants absorb toxins from the soil? Consider a plant like Aloe Vera that grows up in a toxic environment where the concentration of pesticides, and materials like lead, mercury, cadmium, arsenic etc is very high(e.g. Marshland dumping yard ). Would that mean that the extract from these plants would contain all these toxic elements. Not "all of them". But yes, plants suck up water from the soil, with everything dissolved in this water - nutrients, heavy metals, poisons. And also they breathe air, and absorb stuff via this route.
There probably are some toxins which will not enter the plant, because their molecules are too large and/or fragile. For example, should a plant root come in contact with snake venom, I cannot imagine that any venom will end up stored in the plant leaves.
Plants also have their own metabolism, so they will change/deactivate some toxins. I've seen claims that some plants "purify" formaldehyde, although I don't trust the sources enough to be sure of that.
But the smaller the poison molecule, and the less similar to stuff which is usually digested in nature, the more likely that it will enter the plant and stick around instead of being broken down. The heavy metals you mentioned are prime candidates. If they are present in the groundwater - or also lead from air pollution, before we banned leaded gasoline - they end up in plants, including food plants. And mushrooms are even more at risk.
Growing food near waste dumps is a known problem in farming, and sometimes makes the news, for example here:
http://bigstory.ap.org/article/mafia-toxic-waste-dumping-poisons-italy-farmlands
The following is multiple choice question (with options) to answer.
In order for crops to grow food safely pesticides are used on them. When it floods, this can cause what to be poisonous? | [
"Corn",
"air",
"Runoff",
"farmers"
] | C | eating food that contains pesticides can have a negative impact on humans |
OpenBookQA | OpenBookQA-2720 | electric-circuits, potential, electrical-resistance, conductors
These analogies are not exact and are only intended to give you a better feel as to what is happening.
Hope this helps.
The following is multiple choice question (with options) to answer.
An example of an electrical circuit running properly would be | [
"dimming lights",
"swimming in pools",
"running outside",
"riding bikes"
] | A | when an electrical circuit is working properly , electrical current runs through the wires in that circuit |
OpenBookQA | OpenBookQA-2721 | entomology
Title: What is the name of this tiny creature? It looks like a tiny piece of moving cotton? By chance, I saw this tiny insect on my bag a few days ago in Sydney. Am I the first person who has pinpointed this animal?! If not can you please let me know its name? From your image, it looks like it might be a woolly aphid. I just did a bit of cursory research, and it looks like they're often described as floating pieces of fluff, that seem to wander instead of directly heading somewhere. The fluff on their back is actually wax produced as a defense mechanism from predators and the like. I hope this is what you were looking for!
The following is multiple choice question (with options) to answer.
Some caterpillars use camouflage to look like | [
"Anger",
"poop",
"love",
"Sarcastic"
] | B | An example of camouflage is when something has the same color as its environment |
OpenBookQA | OpenBookQA-2722 | 5. Jul 21, 2014
### George Jones
Staff Emeritus
Related to DH's post:
RMS voltage multiplied by (in phase) RMS current gives average power. Some references call this product RMS power, but this is not correct, it is average power, hence the equivalent brightness of a lightbulb.
The following is multiple choice question (with options) to answer.
which one of these would be needed to power up a torch light? | [
"a hard wood chip",
"a set of AAA cells",
"a metal iron rod",
"a sachet of water"
] | B | a battery is a source of electrical energy |
OpenBookQA | OpenBookQA-2723 | experimental-chemistry, home-experiment, teaching-lab
Title: In which country is it allowed to practice non-clandestine amateur chemistry? I travel a bit so am flexible where I live, and have taken a recent interest in chemistry to try to gain an understanding of physical reality. I find learning from textbooks to be good, but want to have the comfort of applying a lot of this knowledge in my own lab. To see and feel how it works first hand. From my understanding, the west has a huge paranoia with clandestine chemistry, which is of no interest to me. However, it seems a vast quantity of common reagents and catalysts in organic chemistry books are banned in western countries due to this.
Would someone know how it's possible to practice amateur chemistry from home, without fear of accidentally breaking the law by using some reagent I'm not supposed to? And if not, what would be the best way to gain hands-on experience like this, where I can have complete freedom to experiment with what I want to do? I find at university I'm limited to lab sessions, and if one day I gain employment with a lab I'd no doubt not be free to conduct my own experiments. I wish to emphasize, I'm financially independent from my chemical studies, so purchasing the equipment isn't the issue. It's the legality I'm concerned about.
Is there an option to do this, to pursue amateur knowledge in chemistry, or is it illegal? Is there a country in which it isn't illegal? Your question is basically too broad to be answered in full detail. I suggest that if you want a more detailed answer about a certain part, you should open a question for that matter separately. That being said, I'll try to summarize my own experience as a hobby chemist.
First of all, are you actually studying chemistry? IMHO, if this is within your possibilities, it is the best way to gain experience and also do your your own research. You will have supervision and the best equipment available. You will get the space to do research in your own areas mostly during your graduate studies, but here (The Netherlands) you will also get some space as an undergraduate.
Consider the following points (in no particular order):
The following is multiple choice question (with options) to answer.
To get a lab experiment right you need to | [
"use all dirty equipment",
"fully comprehend the instructions before starting",
"do the opposite of what you're supposed to do",
"instead of measuring things, make guesses"
] | B | performing lab expiriments accurately requires understanding all directions beforehand |
OpenBookQA | OpenBookQA-2724 | general-relativity, time, equivalence-principle
the one near the earth will have a greater acceleration than the one on the mountain
Yes; as shown in the indicated answer, the two participants which remain rigid to each other in a flat region move at ("slightly") different constant proper accelerations, too;
namely "the top" moving with proper acceleration $ k \, e^{(\frac{-k}{c^2} L )} $,
compared to "the bottom" moving with proper acceleration $k$,
where $\frac{2 L}{c}$ is the constant ping duration of "the bottom" to "the top" and back.
The following is multiple choice question (with options) to answer.
If one where to get high at Mt. Everest it would mean they are | [
"arriving at airport",
"waiting for cabs",
"at the bottom",
"at the apex"
] | D | high means great in altitude |
OpenBookQA | OpenBookQA-2725 | remote-sensing, forest
Title: How is tree age estimated? I am trying to study about forest biomass and carbon amount of forest.
First of all, I studied some papers, they mentioned that age of forest is related to the biomass. So, How do we measure the age of tree? What are the practical ways used to estimate tree age? Biomass itself isn't a great measure of tree age because the size of a tree is affected by a number of factors. Assuming the same species of tree:
Soil nutrients: more nutrients in general means better growth for most species
Availability of water: scare water means less growth
Availability of light: a tree with more light grows more than one that's constrained
A tree with good soil, lots of water and light will grow more than one without those things, so the same age of tree could be very different sizes and biomasses. The only way to get an exact age of a tree is to get a core sample or cut it down and count the rings, every ring represents a growing year. A tree that grows very little will have narrowly spaced rings, a tree that grows a lot has wider space rings as it's putting more biomass. Note that wood density is also an important measurement for biomass, the denser the wood the more biomass is compacted in the same amount of space. Slower growing trees tend to be more dense, tree twice the size of another may not be twice the mass.
That's for a single tree, but you're asking about forests. It's impractical to core sample a million trees, but you can core sample a fair number of live ones or take samples of fallen ones. Along with measurements of circumference and height you can build a database and estimate the average age of the rest of the trees in the forest from their heights and circumferences. It's also possible to estimate the biomass of the forest from estimating the number of trees in and using an average biomass.
The following is multiple choice question (with options) to answer.
If a tree is being discussed and those talking want to know its age, they will | [
"think about it",
"bury it",
"look at leaves",
"look inside it"
] | D | the number of rings in a tree trunk can be used to estimate the age of the tree |
OpenBookQA | OpenBookQA-2726 | astrophysics, orbital-motion, celestial-mechanics, solar-wind, solar-sails
So a really big coronal mass ejection could indeed significantly boost the thrust from a solar sail, but I think we need to inject a note of reality. Firstly the force is still very small so even for a very large CME our solar sail powered spaceship would not be racing off as if its pants were on fire. Secondly CMEs large enough to dominate the force on the sail are exceedingly dangerous and would probably kill the occupants of the spaceship anyway. And of course thirdly solar flares do not happen to order. So while it is an interesting calculation, I don't think surfing a solar flare is likely to be a useful way of propelling a spaceship any time soon.
The following is multiple choice question (with options) to answer.
Igniting the shuttles boosters causes it to | [
"explode",
"stop midair",
"accelerate",
"decelerate"
] | C | force causes the speed of an object to increase |
OpenBookQA | OpenBookQA-2727 | atmosphere, ocean, hydrology, climate-change
Comment: I strongly endorse the use of wind and hydropower as sources of energy over the further use of fossil fuels. However, I still think it is important to do research into the actual renewability of presumed-renewable energy sources, as we don't want to end up with another fossil fuel-type situation, in which we become aware of dependency on these energy sources and their malignant environmental side-effects long after widespread enthusiastic adoption. Electricity from waves, from hydro (both run-of-river and storage) and from wind, are all indirect forms of solar power. Electricity from tides is different, and we can deal with that in a separate question. Global tidal electricity generation is not yet at the scale of gigawatts, so it's tiny for now.
Winds come about from the sun heating different parts of the planet at different rates, due to insolation angles, varying cloud cover, varying surface reflectivity, and varying specific heat of surface materials. Temperature differentials create wind currents.
Waves come about from wind, so they're a twice-indirect form of solar power.
Sunlight on water speeds up evaporation, lifting the water vapour into clouds, giving them lots of gravitational potential. That rain then falls, sometimes onto high land, from where it can be gathered into storage reservoirs that are tapped for electricity, or where it flows into rivers that are then harnessed in run-of-river hydro.
How much power is there? Well, the insolation from the sun is, at the outer boundary of the Earth's atmosphere, at an intensity of about 1400 Watts per square metre. The Earth's albedo is roughly about 30% - i.e. on average about 400 Watts are reflected back into space, giving an average irradiation into the Earth of about 1000 Watts per square metre. Picture the Earth's surface as seen from the Sun: wherever the Earth is in its orbit on its own axis, and around the Sun, the Sun sees a disc that has the Earth's diameter, so the surface area exposed to the Sun is just $\pi$ times the square of Earth's radius, which is about 6 300 kilometres.
So the incoming solar radiation is $1000 \times 6,300,000^2 \times \pi \approx 125 \times 10^{15} \rm \ W$
The following is multiple choice question (with options) to answer.
Our planet has multiple | [
"moons",
"suns",
"orbits",
"environments"
] | D | the Earth contains many ecosystems |
OpenBookQA | OpenBookQA-2728 | homework-and-exercises, thermodynamics, temperature, everyday-life
Title: Why is my hand not burned by the air in an oven at 200 °C? I have this problem from University Physics with Modern Physics (13th Edition):
The inside of an oven is at a temperature of 200 °C (392 °F). You can put your hand in the oven without injury as long as you don't touch anything. But since the air inside the oven is also at 200 °C, why isn't your hand burned just the same?
The following is multiple choice question (with options) to answer.
If your hand is being burned on a stove | [
"you will feel cool",
"you will be chilled",
"your nervousness will disappear",
"your nerves will make you aware"
] | D | nerves can be used to feel heat and pressure on the skin |
OpenBookQA | OpenBookQA-2729 | Hey, thanks for your help guys. For a minute there, I thought that this theoretical person could not safely expect to live to be 82 years old.
9. Jun 16, 2012
### SW VandeCarr
In fact, on a purely probabilistic basis, for any finite time no matter how large, there is a non zero probability that a person would survive that long. So for a sufficiently large population, there would be a theoretic person that would live 100,000 years. This, of course, has no basis in biology.
In terms of the probability of being murdered, the model would not hold for the 100,000 year old person. In terms of the model, probably the best one can do is assume the proportion of causes of death would be constant. The calculation above needs to be corrected for overall survival in terms of death from any cause.
Last edited: Jun 16, 2012
10. Jun 16, 2012
### viraltux
Interesting... but 0.37% is not that small percentage, don't you think? That means, roughly speaking, that a community of around 300 persons can expect that one of them will be murdered.
If you consider that the number of people we know plus acquaintances can easily be around 300 persons that would mean that most 82 year old persons know of someone in their circles who has been murdered. Mmm... that might be an interesting survey.
11. Jun 16, 2012
### SW VandeCarr
As I said in my previous post, this is a misapplication of statistics. You have to consider survival in terms of all cause death. If you just consider the murder rate, then at some point nearly everyone gets murdered.
12. Jun 16, 2012
### moonman239
I know that.
This person will not die until he reaches age 82, if he is not murdered. As mentioned before, this person has a 68% chance of living to be 82.
13. Jun 16, 2012
### D H
Staff Emeritus
The probability of living to 82 per this problem is 99.63%, not 68%. You missed the decimal point on the 0.37%.
14. Jun 16, 2012
### SW VandeCarr
The following is multiple choice question (with options) to answer.
A person protecting the environment they have control over will most likely | [
"block in their yard",
"salt their whole yard",
"burn trash in their yard",
"flood their whole yard"
] | A | An example of protecting the environment is creating protected areas |
OpenBookQA | OpenBookQA-2730 | biochemistry, botany, plant-physiology, photosynthesis
What are typical characteristics of different plants in this regard? I.e., how do common species of plants manage their C consumption before (and after) the development of leaves? There are quite a few questions and thoughts in there, I'll try to cover them all:
First, to correct your initial word equation: During photosynthesis, a plant translates CO2 and water into O2 and carbon compounds using energy from light (photons).
You are correct to assume the C is further used for the growing process; it is used to make sugars which store energy in their bonds. That energy is then released when required to power other reactions, which is how a plant lives and grows. C is also incorporated into all the organic molecules in the plant.
Plants require several things to live: CO2, light, water and minerals. If any of those things is missing for a sustained period, growth will suffer. Most molecules in a plant require some carbon, which comes originally from CO2, and also an assortment of other elements which come from the mineral nutrients in the soil. So the plant is completely reliant on minerals.
Most plants, before a leaf is established or roots develop, grow using energy and nutrients stored in the endosperm and cotyledons of the seed. I whipped up a rough diagram below. Cotyledons are primitive leaves inside the seed. The endosperm is a starchy tissue used only for storage of nutrients and energy. The radicle is the juvenile root. The embryo is the baby plant.
The following is multiple choice question (with options) to answer.
Plants use chlorophyll to | [
"get rid of waste",
"absorb energy that the closest star provides",
"keep warm from thermal energy",
"absorb light colored food from the soil"
] | B | chlorophyll is used for absorbing light energy by plants |
OpenBookQA | OpenBookQA-2731 | biochemistry, botany, plant-physiology, photosynthesis
What are typical characteristics of different plants in this regard? I.e., how do common species of plants manage their C consumption before (and after) the development of leaves? There are quite a few questions and thoughts in there, I'll try to cover them all:
First, to correct your initial word equation: During photosynthesis, a plant translates CO2 and water into O2 and carbon compounds using energy from light (photons).
You are correct to assume the C is further used for the growing process; it is used to make sugars which store energy in their bonds. That energy is then released when required to power other reactions, which is how a plant lives and grows. C is also incorporated into all the organic molecules in the plant.
Plants require several things to live: CO2, light, water and minerals. If any of those things is missing for a sustained period, growth will suffer. Most molecules in a plant require some carbon, which comes originally from CO2, and also an assortment of other elements which come from the mineral nutrients in the soil. So the plant is completely reliant on minerals.
Most plants, before a leaf is established or roots develop, grow using energy and nutrients stored in the endosperm and cotyledons of the seed. I whipped up a rough diagram below. Cotyledons are primitive leaves inside the seed. The endosperm is a starchy tissue used only for storage of nutrients and energy. The radicle is the juvenile root. The embryo is the baby plant.
The following is multiple choice question (with options) to answer.
What do plants do after they use their chlorophyll to make energy from sunlight? | [
"use it right away",
"sell it to someone",
"save it for future use",
"give it to a friend"
] | C | usually plants store the food they produce for future use |
OpenBookQA | OpenBookQA-2732 | zoology, ecology, species-distribution, migration
Title: How do animals end up in remote areas? I was thinking specifically about random marshy water holes on farmers fields. It seems that you can visit just about any one of these and you will find frogs if you look hard enough.
They usually don't seem to be connected to each other. If it were any other land animal I would figure they walk from one spot to another, but in the case of frogs, I don't imagine their range is very vast. But often these marshy spots can be separated by fairly large distances to a frog.
So this brings me to my question: how do each of these spots end up with frogs in them? I don't imagine a frog is going to go hopping over a hill to get to a marsh on the other side, is it? This question pertains to organism dispersal, which is a very active field of study with relation to it's impact on conservation efforts. Much of what I will say below has been covered in this wiki.
Definition: From the Wiki
Technically, dispersal is defined as any movement that has the
potential to lead to gene flow.
It can be broadly classified into two categories:
Density dependent dispersal
Density independent dispersal
The question of frogs and fishes both refer to Density independent dispersal, while an example of density independent dispersal can be the competition for habitat space between big cats and humans (this is a WWF pdf)
From the wiki:
Density-independent dispersal
Organisms have evolved adaptations for dispersal that take advantage
of various forms of kinetic energy occurring naturally in the
environment. This is referred to as density independent or passive
dispersal and operates on many groups of organisms (some
invertebrates, fish, insects and sessile organisms such as plants)
that depend on animal vectors, wind, gravity or current for dispersal.
Density-dependent dispersal
Density dependent or active dispersal for many animals largely depends
on factors such as local population size, resource competition,
habitat quality, and habitat size.
Currently, some studies suggest the same.
This study in particular studied the movement and habitat occupancy patterns within ephemeral and permanent water bodies in response to flooding. They found that during flooding these frogs moved out to flooded ephemeral water bodies and later on moved back again to the permanent ones.
Other suggested readings for those highly interested in the subject may include this (a phd thesis) and this (a project report)
The following is multiple choice question (with options) to answer.
migration is when animals travel from the northern state such as north dakota to Texas during what segment of time? | [
"lake fronts",
"birds",
"spring",
"winter"
] | D | An example of migration is birds flying south in the winter |
OpenBookQA | OpenBookQA-2733 | physical-chemistry, aqueous-solution, gas-laws, vapor-pressure
An example of this situation playing out in the environment can be seen in the growth of water and ice particles in clouds. The vapor pressure of one particle can differ from that of another due to solute concentration, particle size (small droplets have a greater vapor pressure than larger droplets) and phase (supercooled water droplets have a greater vapor pressure than ice particles at the same temperature). Regardless of the cause of the vapor pressure difference, whether it's solute concentration or one of the other factors, the situation is the same as depicted in your question. And the result is the same; the particles having greater vapor pressure will end up evaporating and then condensing onto the particles having lower vapor pressure (of course we're talking about vapor pressure of water/ice only, not any solute). This is generally referred to as the Wegener–Bergeron–Findeisen process, although this technically only refers to water-to-ice vapor transfer.
The following is multiple choice question (with options) to answer.
Which is the best example of condensation? | [
"cats lick their fur",
"headphones fall into a puddle",
"hail falls from the sky",
"water forms on a frosty beverage"
] | D | condensing causes a liquid to form |
OpenBookQA | OpenBookQA-2734 | atmosphere, ocean, hydrology, climate-change
Comment: I strongly endorse the use of wind and hydropower as sources of energy over the further use of fossil fuels. However, I still think it is important to do research into the actual renewability of presumed-renewable energy sources, as we don't want to end up with another fossil fuel-type situation, in which we become aware of dependency on these energy sources and their malignant environmental side-effects long after widespread enthusiastic adoption. Electricity from waves, from hydro (both run-of-river and storage) and from wind, are all indirect forms of solar power. Electricity from tides is different, and we can deal with that in a separate question. Global tidal electricity generation is not yet at the scale of gigawatts, so it's tiny for now.
Winds come about from the sun heating different parts of the planet at different rates, due to insolation angles, varying cloud cover, varying surface reflectivity, and varying specific heat of surface materials. Temperature differentials create wind currents.
Waves come about from wind, so they're a twice-indirect form of solar power.
Sunlight on water speeds up evaporation, lifting the water vapour into clouds, giving them lots of gravitational potential. That rain then falls, sometimes onto high land, from where it can be gathered into storage reservoirs that are tapped for electricity, or where it flows into rivers that are then harnessed in run-of-river hydro.
How much power is there? Well, the insolation from the sun is, at the outer boundary of the Earth's atmosphere, at an intensity of about 1400 Watts per square metre. The Earth's albedo is roughly about 30% - i.e. on average about 400 Watts are reflected back into space, giving an average irradiation into the Earth of about 1000 Watts per square metre. Picture the Earth's surface as seen from the Sun: wherever the Earth is in its orbit on its own axis, and around the Sun, the Sun sees a disc that has the Earth's diameter, so the surface area exposed to the Sun is just $\pi$ times the square of Earth's radius, which is about 6 300 kilometres.
So the incoming solar radiation is $1000 \times 6,300,000^2 \times \pi \approx 125 \times 10^{15} \rm \ W$
The following is multiple choice question (with options) to answer.
The Earth's energy creates | [
"Happiness",
"Love",
"Anger",
"a magnetic creation"
] | D | the Earth absorbs more energy than it loses |
OpenBookQA | OpenBookQA-2735 | human-biology
Title: Do biological facts determine when a human fetus is considered alive and human? I often hear or read this statement:
"It's not a human, it's a fetus."
In other words, some think a fetus is non-human until a certain point.
And another similar statement:
"The fetus isn't alive until 26 weeks of gestation."
So some think the fetus is not actually "alive" until a certain point.
What does biology have to say about these two statements?
I encounter these statements often in discussions about abortion, but that issue, and other similar philosophical issues, are outside this question. I'm wondering strictly from a scientific/biological standpoint: are these statements true?
Is the fetus in a human mother non-human until a certain point?
Does the fetus not classify as "alive" until a certain point?
The people I encountered truly believed these statements (3 of the 4 in mind also claimed science was on their side), so it's not as if the question has no merit. I assumed that in the realm of science and biology, there must be a convincing and sure answer. Life is generally distinguished from non-life by metabolism and growth. As such, a fetus is alive. The reference to "not...until 26 weeks gestation" that you've heard likely refers to viability.* With the most aggressive medical care, this is the approximate age when a fetus may be able to survive outside the womb.
The term human from a biologic perspective is a species label.** Given that a fetus is genetically indistinguishable (in broad strokes) from a post-natal human, I think it would be hard to argue that it is anything other than human.
Summary: Yes, a human fetus is both alive and human.
*Note that this use of the word viable is standard but deviates somewhat from the etymology of the word.
**I'm ignoring here other ancient species (homo-) which may be considered human but are irrelevant to the question.
The following is multiple choice question (with options) to answer.
If a thing is procreating, then it is | [
"under age",
"too old",
"young",
"aged enough"
] | D | reproduction occurs during adulthood |
OpenBookQA | OpenBookQA-2736 | astrophysics
Or, in other words, under the inelastic assumption the decrease in velocity per collision is $$~9.79\times10^{-26}\dfrac{m}{s}$$
At 1-2 protons per second, the craft would require ~$10^{26}$ seconds to slow down by 1 meter per second. This is several orders of magnitude greater than the life of the universe.
This simple calculation of course does not take into account collisions with larger objects, or dust particles, but a simple adjustment in mass parameter plus knowledge of the number of collisions would allow for a reasonable estimate. A slightly more sophisticated calculation would consider elastic collisions, which I might add later.
The following is multiple choice question (with options) to answer.
How many seconds would it most likely take to get to Mars? | [
"4000000000000000000000 seconds",
"40 seconds",
"400 seconds",
"4 seconds"
] | A | seconds are used to measure time |
OpenBookQA | OpenBookQA-2737 | If the question is asking for the probability that either of the two cows is 2-coloured, we have
$$P(\text {1 cow is 2-coloured | both visible sides are black}) = \frac{P(\text {1 cow is 2-coloured and other is black}) \times P(\text {the black side of the 2-coloured cow is seen})}{P(\text{both visible sides are black})}=\frac{\frac{\binom{3}{0}\binom{1}{1}\binom{2}{1}\cdot\frac{1}{2}}{\binom{6}{2}}}{\frac{\binom{3}{0}\binom{1}{1}\binom{2}{1}\cdot\frac{1}{2}}{\binom{6}{2}}+\frac{\binom{3}{0}\binom{1}{0}\binom{2}{2}}{\binom{6}{2}}}=\frac{1}{2}$$
where $$\frac{1}{15}=\frac{\binom{3}{0}\binom{1}{1}\binom{2}{1}\cdot\frac{1}{2}}{\binom{6}{2}}$$ is the probability that the $2$ visible sides are black when one is 2-coloured and the other is black and $$\frac{1}{15}=\frac{\binom{3}{0}\binom{1}{0}\binom{2}{2}}{\binom{6}{2}}$$ is the probability that the $2$ visible sides are black when both cows are black (these exhaust all possibilities for both visible sides being black).
The following is multiple choice question (with options) to answer.
A kumquat is more likely than a steak to have | [
"fluid",
"seeds",
"fibers",
"skin"
] | B | fruit contains seeds |
OpenBookQA | OpenBookQA-2738 | newtonian-mechanics, newtonian-gravity, universe
Title: What would happen to an object if one was to drop it in intergalactic space? This might be a dumb question but i was confused as to what would happen if one was to somehow drop an object in intergalactic space. For example when something is dropped on earth it falls to the ground due to the gravity, but if we was to drop an object in intergalactic space where no large object is near, what would happen to said object? would it just float in the direction of Largest object near by?
but if we was to drop an object in intergalactic space where no large
object is near, what would happen to said object? would it just float
in the direction of Largest object near by?
The short answer is it might "float" (not accelerate) for a while, but probably not for long.
The Newtonian force of gravity has an infinite range. There is nowhere in space not under the influence of gravity, no matter how far from gravitating bodies. While the net gravitational force may be very small at a particular point in space, and even zero at times, gravitating bodies are constantly on the move. So net gravitational force at a particular point in space relative to other bodies is constantly changing.
if it would be placed where the net gravitational force was 0 and it
was placed by someone stationary what would happen? would it just be
still?
You need to understand that nothing in the universe is "still". Even if not accelerating, everything is in motion relative to something else. No net force does not mean something is still. It only means it is not accelerating. Your computer on your desk appears to be still to you. But relative to someone driving at constant velocity and looking at your computer through your window, your computer and you, and your house for that matter, are moving relative to them.
Since everything is moving relative to other things, the distance between things is constantly changing. The gravitational forces, which depend on the separation of things, also changes.
Hope this helps.
The following is multiple choice question (with options) to answer.
If an entity in intergalactic space has thrust placed upon it, what is the expected result? | [
"it will start moving with acceleration",
"it will make a loud noise",
"spontaneously teleport a light year away",
"remain in the same location"
] | A | a rocket engine is used to produce thrust by pushing gases out at a high speed |
OpenBookQA | OpenBookQA-2739 | food, nutrition
Supplements aren't intended to be a food substitute because they can't replicate all of the nutrients and benefits of whole foods, such as fruits and vegetables.
and there are three main differences:
Greater nutrition. Whole foods are complex, containing a variety of
the micronutrients your body needs — not just one. An orange, for
example, provides vitamin C plus some beta carotene, calcium and
other nutrients. It's likely these compounds work together to produce
their beneficial effect.
Essential fiber. Whole foods, such as whole grains, fruits,
vegetables and legumes, provide dietary fiber. Most high-fiber foods
are also packed with other essential nutrients. Fiber, as part of a
healthy diet, can help prevent certain diseases, such as type 2
diabetes and heart disease, and it can also help manage constipation.
Protective substances. Whole foods contain other substances important
for good health. Fruits and vegetables, for example, contain
naturally occurring substances called phytochemicals, which may help
protect you against cancer, heart disease, diabetes and high blood
pressure. Many are also good sources of antioxidants — substances
that slow down oxidation, a natural process that leads to cell and
tissue damage.
So you could live off of some meal replacement shake for the rest of your life but should you? Probably not.
The following is multiple choice question (with options) to answer.
Having food has a positive impact on the health of what? | [
"organism charts",
"water",
"sunlight",
"critters"
] | D | having food has a positive impact on an organism 's health |
OpenBookQA | OpenBookQA-2740 | rocks, remote-sensing, archaeology, ground-truth
Together, #1, #2, and #3 tell us that it's probably early summer just after the river ice has broken up.
The tooth-like features in the left image are simply erosional remnants sticking out of the riverbank. They could be bedrock (not likely), ice wedges, unmelted permafrost, or simply dirt. They are on the outside of a meander, so the river is actively cutting into them, and so the river-facing faces are quite sheer and high compared to the slopes in between. The right side might be white because the conditions there had left the snow unmelted when the image was taken. And of course their shadows are longer because the river channel is at the bottom of the bluff.
If you use Google Maps or Earth to go downriver a bit (up and to the left), you will see similar features sticking out of the riverbank, but because they're at a different angle from the features in your image, the fact that they're natural is more readily apparent.
Although the terrain is much less regular on the right side of the image, again the long shadows tell the tale. There are some round lumps that may be pingoes. The shadow that looks like a man is just a coincidental jumble of shadows from the broken terrain. If you look closely at the lump that is supposed to be the "man" (which would technically be an inunnguaq) does not have any protrusions that correspond to the "arms". The "arms" are the shadow of a little cliff or shelf past the lump, which is overlapped by the lump's larger shadow.
It's similar in effect to the infamous misinterpretation of a Viking orbiter image of a natural feature on Mars as a "Face on Mars".
This is a good example of the complications of image interpretation, specifically, understanding the conditions under which the image was taken. It's also a good time to emphasize the importance of doing ground truth when interpreting images. So when you go there, let us know what you find.
The following is multiple choice question (with options) to answer.
The cracks in a sidewalk could be caused by | [
"black holes",
"Pine",
"time travel",
"emotions"
] | B | if a tree is located near a sidewalk then the roots of that tree might crack the sidewalk |
OpenBookQA | OpenBookQA-2741 | botany, plant-physiology, plant-anatomy
It made me wonder if we are simulating the sun in a dark room for growing the plants with the help of red, blue, and a little bit of far-red light, what will happen to the plants if we keep the ideal conditions for which the plants carry out photosynthesis whole day? Does it affect its yield or the plants die out quick?
I am an engineering student working on indoor farming, my knowledge of botany is the same as a high school student. So if I am wrong please tell me. Ideal conditions for photosynthesis
You mention ideal conditions to carry out photosynthesis, I would just like to point out that this includes carbondioxide levels, temperature, and nutrients as well as light.
Flowering
As anongoodnurse mentions performance might be measured by blooming which, in most flowering plants, has a day-light related component. However, for general growth increasing daylight over the 'natural' day length can often increase yield.
Daylight Cycles
The important point to note is that plants do 'ramp up' at dawn getting ready to start photosynthesizing (for some plants with temporal photosynthesis mechanisms (see CAM photosynthesis) this can be even more important). The reason plants do this is because plants can suffer from 'photobleaching' which can be considered similar to sunburn in humans, if they are not ready for sunlight. Getting 'ready' can involve lots of things including opening stomata (pores) to let CO2 in, changing which metabolic pathways are active, and moving about chloroplasts inside cells. Plants 'figure out' how and when to ramp up based on circadian rhythms which work well on 24 hour clocks and slight changes over time. Thus 12 hrs to 16 hrs can be a big change, particularly if the change happens by lights coming on earlier. Additionally, the 24 hour 'clock' means that plants will do better with 18hr light then 6hrs dark cycles than 36hrs light 6 hrs dark, because the total cycle length should be about 24hrs.
Photosynthesis Side Effects
The following is multiple choice question (with options) to answer.
If plants are chilled in evening air, | [
"put them in a fire pit",
"put them in a glass pile",
"put them in an igloo",
"put them in a glass building"
] | D | a greenhouse is used to protect plants by keeping them warm |
OpenBookQA | OpenBookQA-2742 | we simply assume that (a, b) and (b, a) are in the relation, and then we show that a = b. Consider the ≥ relation. As it turns out, the relation 'is divisible by' on the integers is an antisymmetric relation. Spanish Grammar: Describing People and Things Using the Imperfect and Preterite, Talking About Days and Dates in Spanish Grammar, Describing People in Spanish: Practice Comprehension Activity, Delaware Uniform Common Interest Ownership Act, 11th Grade Assignment - Comparative Analysis of Argumentative Writing, Quiz & Worksheet - Ordovician-Silurian Mass Extinction, Quiz & Worksheet - Employee Rights to Privacy & Safety, Flashcards - Real Estate Marketing Basics, Flashcards - Promotional Marketing in Real Estate, DSST Technical Writing: Study Guide & Test Prep, DSST Computing and Information Technology: Study Guide & Test Prep, High School Physics Curriculum Resource & Lesson Plans, Quiz & Worksheet - Characteristics & Types of Food Allergies & Intolerance, Quiz & Worksheet - History of Central American Independence, Quiz & Worksheet - Applying the Work-Energy Theorem, Quiz & Worksheet - Kinetic & Potential Energy of Simple Harmonic Motion, Stereotypes in Late Adulthood: Factors of Ageism & Counter-Tactics, Illinois Science Standards for First Grade, How to Become a National Board Certified Teacher, Arkansas Science Standards for Kindergarten, Parallel & Perpendicular Lines Lesson Plan, Tech and Engineering - Questions & Answers, Health and Medicine - Questions & Answers, Working Scholars® Bringing Tuition-Free College to the Community. Partial and total orders are antisymmetric by definition. That is, if a and b are integers, and a is divisible by b and b is divisible by a, it must be the case that a = b. What is the Difference Between Blended Learning & Distance Learning? Well-founded if for every set which meets the field of , whose preimage under does not meet . Definition of antisymmetric in the Definitions.net dictionary. The number of students in the class is divisible by the number of cookies. Clarifying the definition of antisymmetry (binary relation properties) Hot Network Questions If we write it out it becomes: Dividing both sides by b gives that 1 = nm. Difference Between Asymmetric & Antisymmetric Relation. Question 1: Which of the following are antisymmetric? Definition 1: A relation R over
The following is multiple choice question (with options) to answer.
Which of the following relationships is true? | [
"Play-Doh can scratch diamond, therefore it is softer",
"Diamond can scratch Play-Doh, therefore Play-Doh is harder",
"Diamond can scratch Play-Doh, therefore diamond is harder",
"Play-Doh can scratch diamond, therefore it is harder"
] | C | if one mineral can scratch another mineral then that other mineral is softer than that one mineral |
OpenBookQA | OpenBookQA-2743 | theory, programming-contest
Title: Are there any (theoretical-esque) computer science "competitions" at Undergrad level similar to Putnam? I have searched for a bit eventually arriving at well known websites like codeforces, atcoder, codewars, codinggame or the various OJs.
They mostly involve solving tasks where usually the main focus is elementary discrete maths + data structures and algorithms.
However, I cannot find any that target the more theoretical side of Computer Science with topics including Complexity, Theory of Computation, Logic, Algorithms, Probability & Linear Algebra questions etc.
So do such contests exists? If so, please list!
Bonus if there are any contests for high schoolers as well. The closest thing that I found was the from the Indian based college(?) Chennai Mathematical Institute (CMI)'s STEM's competition for Computer Science (Category A & B).
Some tangentially relevant discussion is in the doi: 10.1007/978-3-319-25396-1_9
The following is multiple choice question (with options) to answer.
Which is competition? | [
"a giraffe eats the highest leaves",
"a bear takes a salmon from the stream",
"a shark eats a tuna that an orca was hunting",
"a slug eats a blade of grass"
] | C | if an animal takes a resource from another animal then that animal competes for resources successfully |
OpenBookQA | OpenBookQA-2744 | zoology, ornithology, ethology, senses, balance
Source: Weimerskirch, H., Bishop, C., Jeanniard-du-Dot, T., Prudor, A. and Sachs, G. (2016). Frigate birds track atmospheric conditions over months-long transoceanic flights. Science, 353(6294), pp.74-78.
PS: You have two questions here, specially after your edit. I suggest that you post another question regarding the spatial orientation, since asking different questions (even if they are related) in the same post is not nice, and it's a reason to close ("Too broad: Avoid asking multiple distinct questions at once"). However, it's worth mentioning that apparently birds do suffer from spatial disorientation when there is no visual cue. According to this relatively old paper, "Spatial Disorientation in Birds":
The only conclusion is that birds are susceptible and suffer from spatial disorientation, and further that the causes of spatial disorientation in birds are exactly the same as those which affect the human pilot, namely; (a) the loss of true visual cues to the horizontal; (b) inexperience in flying under such conditions where visual cues are lost;
The following is multiple choice question (with options) to answer.
If a bird is avoiding detection by a cat simply by sitting still, it probably is also utilizing | [
"eruptions",
"merging with background",
"flames",
"blending paint"
] | B | camouflage is used for hiding by animals against predators |
OpenBookQA | OpenBookQA-2745 | optics, everyday-life, reflection
Title: What are natural retro-reflectors? Recently I was on an airplane on a sunny day. The sun was shining on the other side of the plane and noticed a bright patch on the ground following beside us. Eventually I noticed a dark centre to this bright patch, the plane's shadow, which became more distant as the plane descended. When the plane flew over a city road signs in this bright patch lit up brightly because of their retro-reflective paint.
My question is, what was acting as a retro-reflector to produce this bright patch when it wasn't passing over a road sign? When flying over water the bright patch disappeared, or was very faint. I could see it over forests, more clearly over cut grain fields and, at least faintly over a wide range of terrain. It sounds like a version of the glory, or more likely heiligenschein, due to spherical droplets of water in the air or dew on the ground.
The following is multiple choice question (with options) to answer.
A reflector is used to reflect | [
"light edibles",
"dirt",
"solar heat",
"sunbeams"
] | D | if an object is blue then that object reflects only blue light |
OpenBookQA | OpenBookQA-2746 | statistical-mechanics, atmospheric-science, density
A limnic eruption, also referred to as a lake overturn, is a rare type of natural disaster in which dissolved carbon dioxide (CO2) suddenly erupts from deep lake waters, forming a gas cloud that can suffocate wildlife, livestock and humans. Such an eruption may also cause tsunamis in the lake as the rising CO2 displaces water. Scientists believe earthquakes, volcanic activity, or explosions can be a trigger for such phenomenon. Lakes in which such activity occurs may be known as limnically active lakes or exploding lakes.
Picture 1: one of a number of cattle killed by a limnic eruption at Lake Nyos, Cameroon.
We can occasionally prevent the buildup of carbon dioxide by degassing the body of water.
Picture 2: a siphon used by French scientists to de-gas Lake Nyos. The carbon dioxide emerges from its deposits and bubbles into the water, floating to the top.
The following is multiple choice question (with options) to answer.
If a lake begins to overflow after swelling from a storm, species within that water source likely | [
"propagate",
"stagnate",
"crash",
"stall"
] | A | as the available water in an environment increases , the populations of organisms in that environment will increase |
OpenBookQA | OpenBookQA-2747 | paleontology, fossils, desert
Title: Why are many fossils found in deserts? Why are deserts famous for fossils? Is it a coincidence? Some examples:
Giant Catfish Fossil Found in Egyptian Desert
Chile's stunning fossil whale graveyard explained
Giant Dinosaur Fossil Found in Sahara Desert I would contend that the fact that the location is a desert has little to nothing to do in most cases to the existence of fossils at the location. Most of the fossils in the location, at least the ones that make most headlines like major dinosaur deposits, were left there millions of years ago. The fact that a location today is a desert has no indication of what the climate, or even where on the globe that location was 50 or 100 million years ago.
Do not forget about plate tectonics and climate change. One can go to places like the Judith Basin in Montana, a relatively harsh area of North American Bad Lands, desert or near desert like conditions with cold winters and find fields of fossils from animals that are believed to have lived in tropic marshes of in oceans, because at the time those animals lived, what is now Montana was not inland, and was not at a Northern location. Millions of years ago it was an undersea plate, thus it has layers of limestone made from ancient single cell sea creatures and sometimes larger objects that were entrapped and preserved as larger fossils. At other times, those plates rose from the sea floor and homed some of the large creatures, like T-Rex that lived, thrived and sometimes survive as fossils.
Later, that plate move and ended up inland, in what is not North America. Glaciers, wind, and water may have stripped off many layers of deposits and left exposed or close to exposed the layers of interest to fossil hunters. Desert regions tend to be subjected to this type of erosion and exposure making such finds easier. If those same fossils were in and area such as a rich planes area with plentiful plant growth and never subjected to glacial scouring, they could be, and may very well be, right below your feet but under many layers of soil and decaying vegetation, river sediment and other deposits rendering them out of sight and out of reach.
The following is multiple choice question (with options) to answer.
Which of the following would best describe why a lizard would live in a desert? | [
"it can eat bugs and withstand very cold weather",
"it can eat fish and withstand very cold weather",
"it can eat bugs and withstand very hot weather",
"it can eat fish and withstand very cold weather"
] | C | some lizards live in desert habitats |
OpenBookQA | OpenBookQA-2748 | atmospheric-chemistry
But some researchers have argued it does make a notable contribution in the lower atmosphere, but indirectly. There doesn't appear to be a consensus on how big this effect is (and the Wikipedia reference is old and obsolete). The argument for ozone being a notable contributor is based on the following. Hydrocarbon pollution in the lower atmosphere (often from vehicle emissions) leads to a variety of undesirable reactions some of which lead to the production of ozone (as well as many other irritating components of smog). We really don't want too much smog or ozone in the lower atmosphere because it is bad for health. Some have estimated that it also adds to the warming caused by hydrocarbon emissions (exacerbating the warming potential of methane, for example).
It is hard to judge the estimates of its contribution to warming not least because they rely on models of complex reactions caused indirectly by other pollutants. Also, the big issue with emissions leading to ozone are not its contribution to warming but its contribution to pollution which causes direct harm to people in the short term. In fact regulations around emissions has been striving to reduce those emissions since before we started worrying about global warming. And, many countries have sharply reduced them (this is a major reasons why most western countries insist on catalytic converters in their vehicles). We should reduce ozone pollution by reducing the other emissions that cause it and we have been doing that for decades.
I would argue that ozone is essentially irrelevant to global warming. We should strive to reduce it in the lower atmosphere even if we were not worried by global warming. So even if we can't agree on how big its contribution to warming is (which the literature isn't clear on) we should be reducing it as much as we can for more direct reasons.
And, even if we wanted to report its contribution to warming, the best place to account for it is to add it to the contribution of other emissions (eg methane) rather than to account for it separately as we don't directly emit it from anything.
The following is multiple choice question (with options) to answer.
If pollution is caused by many things, it is least likely to be caused by | [
"using styrofoam",
"pedaling forward",
"driving cars",
"smoking cigarettes"
] | B | riding a bike does not cause pollution |
OpenBookQA | OpenBookQA-2749 | species-identification, invertebrates
Title: Identification of odd jellyfish-like creature in the Mediterranean My parents encountered this unknown creature on a beach in Karpathos, Greece.
None of the locals have seen it before, it may be a species that has moved further north due to ocean warming.
Any ideas what it is? It seems to be a "Hula skirt siphonophore" - Physophora hydrostatica
Physophora hydrostatica, also known as hula skirt siphonophore, is a
species of siphonophores in the family Physophoridae.1
https://en.wikipedia.org/wiki/Physophora_hydrostatica
The following is multiple choice question (with options) to answer.
Marine invertebrates are likely to be discovered in | [
"rushing streams",
"backyard ponds",
"clam filled waters",
"local pools"
] | C | coral lives in the ocean |
OpenBookQA | OpenBookQA-2750 | botany, plant-physiology, plant-anatomy
It made me wonder if we are simulating the sun in a dark room for growing the plants with the help of red, blue, and a little bit of far-red light, what will happen to the plants if we keep the ideal conditions for which the plants carry out photosynthesis whole day? Does it affect its yield or the plants die out quick?
I am an engineering student working on indoor farming, my knowledge of botany is the same as a high school student. So if I am wrong please tell me. Ideal conditions for photosynthesis
You mention ideal conditions to carry out photosynthesis, I would just like to point out that this includes carbondioxide levels, temperature, and nutrients as well as light.
Flowering
As anongoodnurse mentions performance might be measured by blooming which, in most flowering plants, has a day-light related component. However, for general growth increasing daylight over the 'natural' day length can often increase yield.
Daylight Cycles
The important point to note is that plants do 'ramp up' at dawn getting ready to start photosynthesizing (for some plants with temporal photosynthesis mechanisms (see CAM photosynthesis) this can be even more important). The reason plants do this is because plants can suffer from 'photobleaching' which can be considered similar to sunburn in humans, if they are not ready for sunlight. Getting 'ready' can involve lots of things including opening stomata (pores) to let CO2 in, changing which metabolic pathways are active, and moving about chloroplasts inside cells. Plants 'figure out' how and when to ramp up based on circadian rhythms which work well on 24 hour clocks and slight changes over time. Thus 12 hrs to 16 hrs can be a big change, particularly if the change happens by lights coming on earlier. Additionally, the 24 hour 'clock' means that plants will do better with 18hr light then 6hrs dark cycles than 36hrs light 6 hrs dark, because the total cycle length should be about 24hrs.
Photosynthesis Side Effects
The following is multiple choice question (with options) to answer.
What purpose does a plant light serve? | [
"Comfort them",
"replicate sunlight",
"Protect from bugs",
"Keep plants warm"
] | B | a plant requires sunlight to grow |
OpenBookQA | OpenBookQA-2751 | the-moon, earth, angular-diameter
I should mention that these calculations assume the the Earth and Moon are perfect spheres, separated by a constant distance. In reality, none of those things are true, so the true angular sizes of the Earth and Moon are a little different to what I've calculated above.
As ProfRob says, the Earth isn't a perfect sphere. It's slightly flattened at the poles, with a flattening factor of $f\approx 1/298.25642$. The Moon is also flattened, but much less than the Earth ($f\approx 1/830$), due to its much slower rate of axial rotation.
Also, the orbit of the Moon & Earth about their barycentre is moderately eccentric, with a mean value of $\varepsilon\approx 0.0549$, and the eccentricity changes depending on the distance to the Sun.
Here's a daily plot of the Earth-Moon distance for 2020, produced using Horizons.
The following is multiple choice question (with options) to answer.
How many revolutions does the moon make around the Earth during spring? | [
"twelve",
"three",
"one",
"six"
] | B | the moon is the celestial object that is closest to the Earth |
OpenBookQA | OpenBookQA-2752 | human-biology, cell-biology
Title: Body's decomposition Does a human body decompose in a completely sterile environment ? If yes, what decomposes it ? And how fast ? What happens in vacuum ? Can it remain exactly the same ?
Thanks
Does a human body decompose in a completely sterile environment ?
No it wont. Unstable molecules like ATP will quickly degrade spontaneously. The stable ones like many proteins and lipids wont degrade spontaneously. Enzymes are essential to degrade them and are to be supplied extraneously.
What happens in vacuum ?
Body will dry up :P
The following is multiple choice question (with options) to answer.
Decomposer is a kind of role in our | [
"environment",
"play",
"home",
"army"
] | A | decomposer is a kind of role in an ecosystem |
OpenBookQA | OpenBookQA-2753 | zoology, physiology, brain, ethology, behaviour
Vallortigara, G., Rogers, L. J. & Bisazza, A. (1999). Possible evolutionary origins of cognitive brain lateralization. Brain Research Reviews, 30, 164–175.
Wells, D. L., & Millsopp, S. (2009). Lateralized behaviour in the domestic cat, Felis silvestris catus. Animal Behaviour, 78(2), 537-541.
Zucca, P., Palladini, A., Baciadonna, L. and Scaravelli, D. (2010). Handedness in the echolocating Schreiber's long-fingered bat (Miniopterus schreibersii). Behavioural processes, 84(3): 693-695.
The following is multiple choice question (with options) to answer.
A badger is birthed with behaviors that are | [
"learned",
"found",
"intuitive",
"useless"
] | C | an animal knows how to do instinctive behaviors when it is born |
OpenBookQA | OpenBookQA-2754 | ocean, ocean-currents, tides
Physical effects, then, are likely to include direct effects on current speed, sediment, and stratification.
The obvious possible biological effect is from collisions. This is not my field, but as I understand it no effect is likely on small fish populations from collisions, although individuals may be affected. Collision risk for large animals (e.g. sharks and marine mammals) and for diving birds is a topic of active research, and is likely (especially for mammals) to depend on their behaviour around the devices. No large animal collisions have been reported on any of the prototypes undergoing testing so far.
A good review of possible effects on benthic organisms is provided by Shields et al (2011). These may include,
The following is multiple choice question (with options) to answer.
Small fish can be safe swarming dangerous sharks when | [
"they are hungry",
"they are symbiotic",
"they are starving",
"they are delicious"
] | B | remora fish eat food by attaching themselves to sharks and eating the food left behind |
OpenBookQA | OpenBookQA-2755 | Iv found the co-ordinates of Q relative to P at t=0
---->X=(10,10)km
iv also found the velocity of Q relative to P----> V= V[Q] -V[P]
-----.V= (0,40) - V(30,0)
----- V= (-30,40)km/h
4. Originally Posted by dopi
A ship P is travelling due East at 30 km/h and a Ship Q is travelling due South at 40 km/h.
Both ships keep constant speed and course. At t=0 they are each 10 km from the point of intersection of their courses and moving towards the point.
Hello, dopi,
with your problem you use automatically a coordinate system: The pos. x-axis points to East and the pos. y-axis points to North.
At the time t = 0 the ship P is at P(-10, 0) and the ship Q is at Q(0, 10). The movement of both ships is described by a straight line. The speed is described by a vector:
$\overrightarrow{v_P}=(30, 0)$
$\overrightarrow{v_Q}=(0, -40)$
Thus P is moving along the line:
$\overrightarrow{x_P}=(-10, 0)+t*(30, 0)$
and Q is moving along the line:
$\overrightarrow{x_Q}=(0, 10)+t*(0, -40)$
The distance between the ships is: $\vec{d}=\overrightarrow{x_P}-\overrightarrow{x_Q}$
Originally Posted by dopi
Iv found the co-ordinates of Q relative to P at t=0
---->X=(10,10)km
The following is multiple choice question (with options) to answer.
A ship navigates with a magnetic compass because it is | [
"predictable",
"unpredictable",
"waterproof",
"tradition"
] | A | Earth 's magnetic patterns are used for finding locations by animals that migrate |
OpenBookQA | OpenBookQA-2756 | reproduction, digestion, sexual-reproduction
Hazardous components of pollen:
Trace amounts of hepatotoxic pyrrolizidine alkaloids were found in pollen of Echium vulgare, E. plantagineum, Senecio jacobaea, S. ovatus, and Eupatorium cannabinum (Boppre et al., 2008). In Middle and Northern Europe these pollens are not among the main pollen grains gathered by bees, however in Southern Europe the two Echium plants are more diffused and are gathered by bees in larger amounts (Campos et al., 1994; Serra Bonvehi, 1997). [Source 1] (Page 5)
Therefore, it should undergo tests to approve it's purity as allergies can be caused.
References:
1 : Future of bee pollen(Research gate)
2 : Pollen composition and standardisation of analytical methods(Research gate)
3 : Hollow pollen shells to enhance drug delivery(NCBI)
4 : Bee pollen: chemical composition and therapeutic application(NCBI)
5 : Biological activities of commercial bee pollens: antimicrobial, antimutagenic, antioxidant and anti-inflammatory(NCBI)
6 : Biological and therapeutic properties of bee pollen: a review(NCBI)
The following is multiple choice question (with options) to answer.
Which of the following substances likely contains plant seeds? | [
"sweat",
"poop",
"urine",
"blood"
] | B | plant requires seed dispersal for reproduction |
OpenBookQA | OpenBookQA-2757 | hygiene, food-chemistry
Dishes and utensils are only susceptible to bacterial growth if there's traces of food on them. Washing is meant to remove traces of food and oil so bacteria can't multiple on them. The conditions must be right for bacteria to multiple. If traces of food were to be completely dry and hardened on a dish and someone ate off it, the likelihood of any bacteria present on it is close to nil. They need moisture to grow. If dishes had no oily food on them, washing and rinsing with very warm water would be sufficient. I've seen people from other cultures wash dishes with traces of food that are soluble in water. They come out perfectly clean. (As an aside, using a tea towel can often spread bacteria when they're not used properly.) Towels top kitchen contamination hazards list
Bacteria can't multiple in oil. For example, ordinary cooking oil doesn't need to be refrigerated although it can go rancid. A cast iron frying pan is properly meant for frying foods only. No watery sauces should be cooked in them. Even "scraping it clean" shouldn't be done with a sharp metal object as it can remove some of the polymerized hardened oil layer.
I have several cast iron pans that I don't wash. I wipe them out after each use, then I add a little oil nd roughly a teaspoon of salt. With a paper towel, I rub at any bits of stuck on food. If done within a few hours of being used, it effectively removes any food traces, leaving a smooth surface. I usually rinse off the salt in warm water, dry it and then apply a very thin film of oil. I've been cooking in cast iron pans for decades and have never gotten sick or had mild food poisoning (what many people call a 'stomach flu').
Cast iron pans with a layer of proper seasoning and treated like this will definitely not cause sickness. It can't support bacterial growth and as @jeanquilt mentions, the pan gets very hot - enough to blister your skin if you touch them with a bare hand.
The following is multiple choice question (with options) to answer.
If a pork chop is underdone, the likelihood of illness spreading to consumers of it is | [
"low",
"nil",
"extreme",
"zero"
] | C | cooking food to proper temperatures protects against food poisoning by killing bacteria and viruses |
OpenBookQA | OpenBookQA-2758 | homework-and-exercises, thermodynamics, thermal-radiation, thermoelectricity
Title: The thermal expansion of material The question is that: they drill a hole in the middle of a metal. Then when this metal is heated, will the hole become larger or smaller? The hole will get bigger, by experiment, but I think that when material expands, the hole must get smaller. What's wrong with this?
In general, can anyone please tell me how material expands exactly? When the metal is heated, all inter-atomic distances increase by the same factor. This drawing may help understand why the hole also increases in size. Here, I increased all distances by a factor a two.
Replace the atoms with galaxies, and you have a model of the expanding Universe, which may help understand why an observer in any galaxy will see herself as the center of the Universe, with all other galaxies flying away from her.
If the hole should shrink, it would mean that some distances should increase more than other. This doesn't happen:
The following is multiple choice question (with options) to answer.
If a thing is going to be able to expand, it will require | [
"nutriment",
"pipes",
"flounder",
"conversation"
] | A | an organism requires energy for growth |
OpenBookQA | OpenBookQA-2759 | mycology
Does this mean that not only is going to the swimming pool not a cure of fungal infections, but it is actually the cause? Well, maybe not. While the articles show that there is a larger incidence of fungal infections among swimmers, they only show correlation, not causality. People who partake in sports activities have a bigger chance of having these infections than the general public. These are also the people who are more likely to go swimming.
To settle the matter for good, we need an article named "Prevalence of fungal infections among occasionally swimming couch potatoes" :-)
The following is multiple choice question (with options) to answer.
If a beach is below a farm it can make swimmers ill if | [
"people go to the movies",
"field fluid drips down",
"humans enjoy eating meat",
"some cattle eat cheese"
] | B | runoff is when cropland water enters bodies of water |
OpenBookQA | OpenBookQA-2760 | 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.
An animal that often lives in holes in the ground in fields has | [
"long curly hair",
"round ears",
"four wings",
"rainbow stripes"
] | B | mice live in in holes in the ground in fields |
OpenBookQA | OpenBookQA-2761 | acoustics, vacuum, frequency, resonance, vibrations
Title: Resonance and natural vibrations in vacuum In my Physics textbook, it says that if two pendulums of the same natural frequency are placed next to each other and if one is set into vibration, the other starts resonating and when the first one gets damped due to air friction, the vibration of the second one again sets the first into vibration (resonance) and this goes on until all the energy is dissipated as sound. My Question is: If placed in vacuum, will these two complement each others' vibrations and continue vibrating in perpetual motion (because there isn't any propagation of sound in vacuum due to absence of a medium)? No, because in a vacuum, there is no way for the two tuning forks (I think you meant this, rather than pendulums) to communicate. The reason a second tuning fork with the same resonance frequency will begin resonating is because, physically, sound waves are hitting it at its natural frequency. Sound waves travel in a medium, so in a vacuum, there's nothing to carry the sound waves and, hence, no communication between the tuning forks.
The following is multiple choice question (with options) to answer.
Which of the following relies on vibrating matter to work? | [
"soda cans",
"dog food",
"baseball caps",
"violas"
] | D | vibrating matter can produce sound |
OpenBookQA | OpenBookQA-2762 | physical-chemistry, acid-base, equilibrium
*There is perhaps some subtlety here. As an example, consider the salt $\ce{MX}$, which dissociates weakly into $\ce{M+}$ and $\ce{X-}$. The intuition behind the greater degree of dissociation is that (1) upon dilution, the equilibrium constant for dissociation doesn't change, whereas (2) the concentration of each species decreases. Because dissociation produces more ions than was originally present, this always leads to $Q < K$, and more dissociation will occur.
If we add a salt $\ce{MY}$, then, we are introducing two effects: (1) decreased concentration of $\ce{X-}$ and (2) increased concentration of $\ce{M+}$. Because these effects pull the equilibrium in opposite directions, we can't conclusively determine what exactly will happen. Going back to your example, if we add a slightly stronger base, then we get exactly these two contrasting effects, and the change in the degree of dissociation is indeterminate. In contrast, if we add a much stronger base, then certainly (2) dominates and the degree of dissociation is reduced.
The following is multiple choice question (with options) to answer.
An example of a chemical change is | [
"milk to yogurt",
"mixing marbles",
"my chemical romance",
"shredding paper"
] | A | An example of a chemical change is acid breaking down substances |
OpenBookQA | OpenBookQA-2763 | a) Assuming that the ball starts with Joan,
what is the probability that she will have it back after 2 throws?
$\begin{array}{cccc} & \text{John} & \text{Joan} & \text{Kim} \\
\text{John} & 0 & \frac{1}{3} & \frac{2}{3} \\ \\[-4mm]
\text{Joan} & \frac{1}{2} & 0 & \frac{1}{2} \\ \\[-4mm]
Then: . $A^2 \;=\;\begin{pmatrix}\frac{1}{3} & \frac{1}{2} & \frac{1}{6} \\ \\[-4mm]
\frac{1}{8} & {\color{blue}\frac{13}{24}} & \frac{1}{3} \\ \\[-4mm]
\frac{3}{8} & \frac{1}{12} & \frac{13}{24} \end{pmatrix}$
Therefore, there is a $\tfrac{13}{24}$ probability that Joan will have the ball after 2 throws.
Correct!
b) Assuming that the ball starts with Kim,
what is the probability that Joan will have it after 3 throws?
We want $A^3.$
The following is multiple choice question (with options) to answer.
if a beach ball explodes, which of these would be given off? | [
"a flock of geese",
"a ton of sand",
"a release of air",
"a release of doves"
] | C | a beach ball contains gas |
OpenBookQA | OpenBookQA-2764 | ros-lunar
Originally posted by alsora with karma: 1322 on 2018-09-08
This answer was ACCEPTED on the original site
Post score: 1
Original comments
Comment by Elric on 2018-09-08:
Thanks a lot. It's an exercise that I have to do in my robotic's subject.
Comment by Elric on 2019-01-22:
Do I need to use Navigation Stack? I want to use Gazebo also.
Comment by alsora on 2019-01-22:
The navigation stack is a "collection" of standard nodes used for navigation.
You should look at it to get an idea of which components do you need.
Then you can either use the included nodes or other similar ones.
There are no requirements between using Gazebo and the navigation stack
Comment by Elric on 2019-04-07:
I'm going to teleop the robot with the keyboard to make the map. I had thought to use gmapping to store the map but it seems that it needs a laser and I can't use it. Any suggestion about how and where to store the map? Thanks.
The following is multiple choice question (with options) to answer.
What is essential for a robot to possess to walk up a flight of stairs? | [
"electricity",
"skittles",
"ethics",
"lava"
] | A | a computer controls a robot |
OpenBookQA | OpenBookQA-2765 | zoology, ethology, behaviour, psychology, death
Strange thought
Organisms that have not evolved the ability to make "conscious choices" cannot decide to end their life. You will be hard-pressed to find any scientific data on this question. Psychology in humans is already a difficult study, at times failing to demonstrate results with real scientific rigor. When studying animal psychology, you face another substantial barrier - language. Although some primates have been taught to communicate with sign language, the best of them are still far from the level of proficiency of a human. We can measure brain activity and observe behavior, which can lead us to strong suspicions about what is going on in an animal's mind, but very little can actually be proven.
Mostly, all we can do is speculate about such questions. You will find some veterinarians out there who treat pets for mental conditions, but you will find at least as many people calling them quacks as those who believe in the validity of their work. And certainly, they can't prove to you that a treatment has helped an animal. It's subjective.
If we see an animal do something which in a human might reliably be interpreted as a sign of depression, it's possible that this interpretation is appropriate for the animal as well. It's also possible that there is some totally foreign unrelated explanation. The problem we find when trying to scientifically discuss matters which cannot be proven scientifically is that scientists must be careful to state what they know and nothing more. So they might say "We cannot prove that the porpoise is depressed", or "Science cannot prove the existence of a God." This is often misinterpreted as evidence against the finding - that the porpoise is not depressed; that there is no God. This is a fallacy. Rather, we should recognize that we have different ways of exploring questions like these.
The following is multiple choice question (with options) to answer.
If you find an animal that isnt breathing, it is safe to assume that thing | [
"watched TV",
"cried",
"perished",
"laughed"
] | C | if a living thing dies then that living thing is dead |
OpenBookQA | OpenBookQA-2766 | the-moon, earth, light, satellite
Title: Why does the Moon appear gray when passing between the Sun and the Earth? Shouldn't the Moon appear as bright as a full Moon seen at midnight from Earth?
The photo was taken by DSCOVR at Lagrange point 1.
In the picture, The Moon appears dark gray. Of course the Earth appears bright, reflecting sunlight from clouds and water. The Moon's surface is gray and should reflect less light than the Earth.
It should be irrelevant that we see the far side, since the reflectivity of the Moon's surface should be the same on the far side as the side that faces the Earth.
The midnight full Moon appears much, much brighter as seen from Earth than it does in this picture, despite the fact that the amount of sunlight reflecting from the surface of the Moon is the same in both instances.
I understand the photo was taken with 3 separate exposures of red, blue and green, but this should not affect the brightness.
So why does it appear so dull? That's what it really would look like if you were there with DSCOVR. The albedo of the Moon is only about 0.136, about half of the Earth's average albedo. Of course the part with clouds is higher.
I was shocked too, but it was explained in written copy that accompanied the release of the original image.
Shouldn't the Moon appear as bright as a full Moon seen at midnight from Earth?
It does. If the moon were a diffuse, white ball, a full moon would be about seven times brighter!
If you watch the image or GIF, the Moon is roughly the same brightness as central Australia or the Sahara region.
Phil Plait explains well in Bad Astronomy.
There's a lot to read here.
EDIT: I just ran across these images of astronauts on the surface while reading this answer. Their suits are not 100% white to begin with, but the Lunar soil - at least in these locations - is significantly darker. It is close to the same color as the (presumably) nearly-black radiator fins for the heat sink of the RTG unit (2nd photo) at the astronaut's foot.
above: "Buzz Aldrin carries the EASEP." from here
above: "Astronaut Alan L. Bean from Apollo 12, put the Plutonium 238Pu Fuel from the Lunar Module into the SNAP 27 RTG" from here.
The following is multiple choice question (with options) to answer.
The moon has | [
"Narwhales",
"Fairies",
"dead volcanoes",
"Unicorns"
] | C | the moon 's surface contains highlands |
OpenBookQA | OpenBookQA-2767 | gravity, earth
This is not enough to send iMerchant into space. However, a component $g_\mathrm{spin} \sin\theta = 4.9\,\mathrm{m}\,\mathrm{s}^{-2}$, or roughly half a G, would point horizontally toward South, enough to send him tumbling down the street, or at least walk awkwardly.
The following is multiple choice question (with options) to answer.
Actress and goddess Jessica Alba wishes to help the environment by riding a bicycle. Dressed in a tantalizingly suggestive outfit, she propels herself by | [
"dark angel wings",
"burning rocket fuel",
"using paparazzi cameras",
"using foot levers"
] | D | pushing on the pedals of a bike cause that bike to move |
OpenBookQA | OpenBookQA-2768 | astronomy, everyday-life, popular-science, climate-science
Title: Why is the summer, in the temperate latitudes, in average, hotter that the spring? It is common knowledge that the transition from the Spring to the Summer season occurs in the Summer Solstice when the "Sun reaches its highest excursion relative to the celestial equator on the celestial sphere" (as stated in Wikipedia).
It is also stated in Wikipedia' Summer page:
"Days continue to lengthen from equinox to solstice and summer days progressively shorten after the solstice, so meteorological summer encompasses the build-up to the longest day and a diminishing thereafter, with summer having many more hours of daylight than spring."
My question is: why is the summer, in the temperate latitudes, in average, hotter that the spring? A major part of the reason for this is due to the temperature of the ground. While the length of days in the Summer are effectively a mirror of those in Spring, you must take into consideration more than that.
When Spring commences in temperate climates, it is (usually) immediately preceded by winter. Due to the Winter, the ground and/or surrounding bodies of water are very cold. This has the effect of cooling the air for the first part of Spring while the ground/water begins to thaw/warm up. Furthermore, it takes much longer to warm or cool a body of water than a mass of air; even longer to warm or cool the ground and water. Therefore, as Spring progresses and the days become longer (also meaning the Sun is higher above the horizon, thus providing more heating power), the sunlight must first overcome the cooling effects of the ground and water bodies. Near the end of Spring - when the days are sufficiently long and the Sun is much higher above the horizon - you should notice the weather becoming hotter. This is because the ground and water has had time to warm up, which means it is not constantly cooling the air and making it feel colder.
When you then transition to Summer, the ground is already sufficiently warm but the days are still long and the Sun is still high in the sky. This means the Sun can heat the ground, water, and air even more and without any cooling effects. This allows the Summer temperature to be easily higher than that of the Spring temperatures. If Summer were immediately preceded by winter, you might notice the weather getting warmer much more quickly, but the average temperature would be very close to that of the Spring.
The following is multiple choice question (with options) to answer.
A boy hates summer with a burning passion, so luckily the longest he should ever have to endure the season is | [
"twelve weeks",
"three years",
"nine months",
"two days"
] | A | a new season occurs once per three months |
OpenBookQA | OpenBookQA-2769 | zoology, ornithology, ethology, behaviour
Title: Crow branch pecking behaviour I was walking through a small park when two crows started cawing at me, and followed me, flying from tree-to-tree as I walked. I speculate that this is a territorial or protective behaviour, but what I found different was the crows were violently pecking the branches nearby them. I have no memories coming to mind of seeing this behaviour beforehand. I speculate that this behaviour could be threat displays, but a quick search on Google did not reveal to me any authoritative studies on this phenomenon. I'd appreciate more information and sources.
This question has been added as a casual observation on iNaturalist. This is a good question. This type of behavior -- pecking at a branch, wiping the side of the beak on a branch, pulling off twigs and dropping them, or knocking off pieces of bark -- is quite common among many corvid species, particularly when they are interrupted by something or someone that they might consider a threat. This includes not only potential predators but also potentially hostile conspecifics.
It is typically considered to be a form of displacement behavior. The concept of displacement behavior, from classical ethology, posits that when an animal experiences two conflicting drives to do two different things, it doesn't know which to do and does a third thing instead to dissipate the drive or anxiety. For branch-pecking in crows, see E.g Kilham and Waltermire 1990 Ch. 12.
Referece: Kilham, L., & Waltermire, J. (1990). The American crow and the common raven. Texas A&M University Press.
The following is multiple choice question (with options) to answer.
If a bird is pecking at a bush for food, the bush can also eat if | [
"munches on some berries",
"it fulfills its role",
"orders something it likes",
"kills a small deer"
] | B | producer is a kind of role in the food chain process |
OpenBookQA | OpenBookQA-2770 | Let $P_k$ denote the event that she is poisoned with the $k$th cup.
Since there are four cups, of which just one contains poison, the probability that she is poisoned with her first cup is $$\Pr(P_1) = \frac{1}{4}$$
To be poisoned with the second cup, she must not have been poisoned with the first cup and then be poisoned with the second cup. The probability that she is not poisoned with the first cup is $\Pr(P_1^C) = 1 - 1/4 = 3/4$. If she is not poisoned with the first cup, there are three cups remaining of which one is poisoned, so the probability that she is poisoned with the second cup if she is not poisoned with the first is $\Pr(P_2 \mid P_1^C) = 1/3$. Hence, the probability that she is poisoned with the second cup is $$\Pr(P_2) = \Pr(P_2 \mid P_1^C)\Pr(P_1) = \frac{3}{4} \cdot \frac{1}{3} = \frac{1}{4}$$
The following is multiple choice question (with options) to answer.
Buttercups can produce | [
"their own nutrients",
"grow in space",
"ride horses",
"enter singing competitions"
] | A | plant cells can perform photosynthesis |
OpenBookQA | OpenBookQA-2771 | entomology, ethology, habitat
Title: Preferred criteria for new bee colony location As a human I want a house with a roof, indoor plumbing, bug free, and make my wife happy. I don't want to drive too far to work, and it has to be well-suited for offspring.
What are the criteria that define a "good spot" for a new location for honey bees. I'm sure it involves water, shade, access to nectar, and defensibility, but I don't know any of the details.
Has anyone ever made measures of this? Beekeepers? Apiologists? What are the things bees think are important, and what values of those do they think are "best"? According to Thomas Seeley, in his book, Honeybee Democracy, he gives the following as important criteria for honeybees when selecting a nest site when a bee colony moves to swarm:
Larger volume (the minimum nesting capacity was found to be around 14 liters with more preference to nests with a capacity of approximately 30 to less than 100 liters)
Relatively small entrance (10 to 30 centimeters squared)
Nest with the entrance located near the floor of a tree cavity
Direction of the nest entrance (south facing for thermoregulation during the winter)
Nest height (preference given to higher nests for colony defense)
Remnants of previous honeycombs (saves work and energy in building the nest structure)
Interestingly enough, bees did not necessarily display a preference for the shape of the entrance, the shape of the nest, the draftiness or dryness of the nest cavity (they are able to plug and waterproof nests).
Flower/nectar/food availability is not necessarily a direct factor as this changes quite frequently throughout the seasons and honeybees are not able to leave their honey stores (which are necessary to sustain the colony throughout the winter) or take them with them every time the colony has trouble finding food. Honeybees have a complex and efficient system for optimized location and sharing of food sources, therefore distance is not as large a factor.
The following is multiple choice question (with options) to answer.
Big flowers have more nectar than small flowers do. Because of this, which flowers will get the most bees? | [
"space cadet",
"smaller ones",
"bigger ones",
"dead ones"
] | C | as the size of a flower increases , the number of pollinators it will attract increases |
OpenBookQA | OpenBookQA-2772 | optics, electromagnetic-radiation, visible-light, reflection, geometric-optics
Title: We know that a window can actually reflect light. But if the window has some dirt sticking to it, the image we see sometimes get magnified. Why? Well, I was traveling in a bus yesterday and saw this occur. The board that separates the passengers from the driver's had something written on it and I saw that the window that was a few meters away from the board reflected all of the things written.. But the window had some dirt on the part where I saw the image of the writings... And, they appeared to be enlarged just at the point where dirt was present. The open spaces between dirt particles each acts like a "pinhole camera" to magnify the image behind the dirty glass pane. The magnification is slight but noticeable. Try this experiment: make a small triangular hole shape by putting three fingertips together so as to leave a gap at their intersection. by pressing your fingertips together, you can make the size of the hole shrink; by relaxing them, you can make the hole larger.
That hole will act as a pinhole camera. now look through the hole at your computer screen from about 24 inches away and vary the hole size. you will find a certain diameter at which the image you see through the hole will get sharper and the text on the screen will become easier to read.
The following is multiple choice question (with options) to answer.
A reflective surface fogging up is | [
"reflection",
"refraction",
"evaporation",
"condensation"
] | D | a phase change is when matter changes from one state into another state |
OpenBookQA | OpenBookQA-2773 | human-biology, respiration
Title: Surviving only on another's exhales? While reading this - Surviving under water in air bubble - this question came to me:
How long can an adult person survive on breathing in only exhales of another adult person? Can this be even calculated by not relying on rough approximations or there are too many variables?
In order CPR (mouth to mouth breathing part) to be effective, logic says that exhaled "air" is not poisonous to bring a fatal blow, but for how long? Ok, I'll bite. Now, I'm going to assume that in this scenario, Alice and Bob are stuck underwater. Alice has a SCUBA tank filled with compressed air (not pure O2) and though she won't share it with Bob, she magnanimously agrees to share her exhaled breaths with him.
Exhaled air contains 13.6–16.0% oxygen and 4.0–5.3% carbon dioxide in addition to other gasses which we'll ignore here. The real question here is: can you survive on that?
13.6–16.0% oxygen is 66%-80% of the amount of oxygen in normal air (which is ~20.1% O2). If we assume that the air pressure of the exhalation is the same as the air pressure at sea level, then the amount of oxygen available to Bob is roughly equivalent to being at an altitude of 2000 - 3500 meters above sea level, which is certainly survivable.
The CO2 is likely to be a bigger problem. CO2 is toxic and, in sufficient quantities, can case asphyxiation even in the presence of sufficient O2. Amounts above 1% can cause drowsiness, headaches, and mild narcosis while higher levels lead to dizziness, confusion, and unconsciousness.
It looks like you need amounts around 7%-10% for death, so Bob will probably survive in the short term, he definitely won't be happy and he won't be doing much. According to wikipedia's page on Hypercapnia, the time one can expect to perform useful activity varies greatly based on the exact amount of CO2:
1 week at 4%,
8 hours at 4.5%,
4 hours at 5%, and
1 hour at 5.5%
The following is multiple choice question (with options) to answer.
Inhaling O2 is a requirement of all | [
"buried animals",
"living animals",
"stuffed animals",
"rocks"
] | B | all animals breathe |
OpenBookQA | OpenBookQA-2774 | physical-chemistry, everyday-chemistry, thermodynamics
As a comparison to this example, let's check out two liquids that do mix.
3. Water and ethanol
For the water, we have basically the same situation as before -- water molecules forming good bonds to each other. The ethanol, though, has an -OH group that can form bonds to the water in the same way that the water does (though not as well). This means that ethanol that mixes with water (and vice versa) will tend to stay mixed, and given that the liquids are being mixed around just by random motions, means that you'll get one mixing with the other just as a matter of statistics.
The following is multiple choice question (with options) to answer.
If substances are combined by pouring them together, they'll mix, such as | [
"salt and oyster crackers",
"lettuce and roma tomato",
"coffee and hazelnut cream",
"whole milk and cheese"
] | C | An example of combining two substances is pouring one substance into the other substance |
OpenBookQA | OpenBookQA-2775 | javascript, optimization, portability, parallax
curPos.top += yStep;
}
if (curPos.top > followPos.top && (yStep >= 0 ? curPos.top > minY : curPos.top < maxY)) {
curPos.top -= yStep;
}
$(jstr).css({ "left": curPos.left, "top": curPos.top });
}, update);
};
The following is multiple choice question (with options) to answer.
If a flag is adjusted at great heights | [
"something is pulled",
"something is ravaged",
"something is burned",
"something is gold"
] | A | a pulley is used to lift a flag on a flagpole |
OpenBookQA | OpenBookQA-2776 | pressure, ideal-gas, evaporation, humidity, condensation
This has important applications in really understanding how things fully work like heat pumps, air dryers, food processing plants, electronics manufacturing, and more.
The following is multiple choice question (with options) to answer.
Where would you point to as an example of condensation, if limited to an office building? | [
"the beads on a cold root beer can",
"the pens leaking ink",
"the vapor rising from the coffee",
"the sprinkler system above"
] | A | beads of water are formed by water vapor condensing |
OpenBookQA | OpenBookQA-2777 | One important takeaway here is that we're not thinking of "implies" in terms of causality or possibility. If you want to talk about such things, we have to go beyond propositional logic - modal logic is a good place to set up shop.
Any if-then statement beginning with "If" and then something that has a value of False (not P in this case) is what's called "vacuously true". In some sense, it doesn't matter whether or not the implication would have held if that false statement after the if were true, because it isn't.
Your reasoning is fine ... but it's just that within the context of logic, any kind of 'if .. then ..' statement is analyzed using the mathematically defined material conditional ... and that can lead to some unexpected results since thate material conditional does not always quite match the English conditional.
So, you didn't "screw up" ... in fact, you were right to question this very result, but there are also excellent reasons for analyzing 'if .. then..' using the material conditional, so you better get used to the material conditional in the context of logic.
If you want to know more about this very issue, I suggest you look up "paradoxes of material implication"
You need to go back to the definition of the implication :
$$\begin{matrix} P & Q & P \Rightarrow Q \\ true & true & true\\ true & false & false\\ false & true & true\\ false & false & true \\ \end{matrix}$$
Now let's adapt it to the proposition ' If (not P) then (not Q)', i.e. $not(P) \Rightarrow not(Q)$:
$$\begin{matrix} P & Q & not(P) & not(Q) & not(P) \Rightarrow not(Q) \\ true & true & false & false & true\\ true & false & false & true & true\\ false & true & true & false & false\\ false & false & true & true & true\\ \end{matrix}$$
The following is multiple choice question (with options) to answer.
Which of the following is likely to be true? | [
"thunder and lightning indicate that there will be acid rain",
"wind indicates a chance of rain",
"fire indicates that there will be rain",
"thunder and lightning indicate a great chance of rain"
] | D | if weather is stormy then there is a greater chance of rain |
OpenBookQA | OpenBookQA-2778 | biophysics, theoretical-biology, ecosystem
Systems ecology, especially with regard to energy and nutrient flow.
This type of ecology can be strongly influenced by physics. For one example see the book Theoretical Ecosystem Ecology: Understanding Element Cycles by Ågren & Bosatta (Ågren was originally a physicist)
Physical limitations to growth and transport
This can include for instance mechanical contraints on plant growth (see e.g. the book Plant Physics by Nicklas & Spatz), water transport in trees (see e.g. this BioSE question) or the biomechanics of movement (see e.g. Hudson et al (2012) on the speed and movement of cheetahs or Wikipedia: Biomechanics).
Allometric relationships between organisms, e.g. with regard to metabolism
To explain these types of relationships knowledge in physics is useful. See e.g. Kleiber's law for more.
MAXENT as a general approach to ecological patterns or to model species distributions
This is basically a tool lifted from physics that can be applied to ecological problems. There are many papers to look at, but Harte & Newman (2014) (Harte is another previous physicist) and Elith et al (2010) are two good starting points.
Dynamical modelling of populations and communities
This field use many of the same tools for analysis as physics, e.g. systems of differential equations. One of the pioneers in this field (among many) were Robert May (also started with a PhD in physics), and his classical book Theoretical Ecology: Principles and Applications is still a good starting point.
Energy harnessing and conversion by organisms
This can refer both to how organsims convert prey to energy (e.g. conversion efficiencies) and the physics of photosynthesis (which is an interesting intersection between physics and molecular biology). See Jang et al (2004) and O'Reilly & Olaya-Castro (2013) for examples of the how quantum mechanics can inform us about photosynthesis.
Hopefully this will give you a sense of some different ways that knowledge in physics can be useful for biology.
The following is multiple choice question (with options) to answer.
Ecosystems | [
"are made up of many plants and lack living animals",
"are communities with a plethora of living beings",
"only contain animals of the same species",
"are present only on certain continents"
] | B | an ecosystem contains large numbers of living organisms in a particular place |
OpenBookQA | OpenBookQA-2779 | wildfire
There are detailed satellite imagery with PM2.5 monitor overlay at Aerosol Watch, if you would like to see how the event progressed through time.
The following is multiple choice question (with options) to answer.
The more often wildfires take place on a space of land, the more often we will see | [
"animal groups in decline",
"animal populations growing larger",
"more birds moving in",
"larger deer starting families"
] | A | as the supply of food in an environment decreases , the population of animals in that environment will decrease |
OpenBookQA | OpenBookQA-2780 | photosynthesis, cellular-respiration, energy, sugar
Basically, points 4-7 convey that Calvin-Benson cycle not only produces sugar but what it actually does is fix inorganic carbon (as CO2) to organic form (in the form of sugar). So, most (practically all) of the carbon that a photosynthetic plant has, comes from this carbon fixation process and that's how plants are photoautotrophic.
The following is multiple choice question (with options) to answer.
During photosynthesis, plants produce sugar that may help with their what? | [
"Babies",
"Love Handles",
"Belly",
"sustenance"
] | D | sugars are transported from the leaves to the roots of a plant |
OpenBookQA | OpenBookQA-2781 | anatomy, scales
If this horse is 500 kg (a mid-range mass for horses), each leg would have to support 125 kg, compared to only 37.5 kg for a 75 kg adult. Why don't we see a corresponding difference in cross-section? Elephant, rhinoceros, &c all have much thicker legs in proportion. The answer, I think, lies in the fact that the animals you mention all evolved as cursorial animals (that is, they run to escape predators). Less mass in the lower leg means it swings easier, so the animal can run faster.
There are two things you're apparently not noticing in that picture. First, the the horse's lower leg is almost entirely bone (and some tendon), and it's bone that does the supporting. The propulsive power comes from the large muscles of the hip, thighs, and shoulders.
Second, the lower part of the leg (with the white wrappings) is not anatomically equivalent to the human's lower leg, but to the bones of the hand and foot. You can see this if you look closely at the rear leg in that picture. The femur, equivalent to the human's thigh, ends at the knee just above the belly line. Then the tibia extends about halfway down, ending at another joint which you might think is the knee, but which is called the 'hock' in horse-speak. The white-wrapped part is a metatarsal, equivalent to human foot bones, then there pastern bones equivalent to human toe bones, ending in the hoof/toenail.
So consider that you can, if reasonably fit, walk around on tiptoe without crushing your foot and toe bones, then imagine the end result of your ancestors having done this for the last several tens of millions of years :-)
PS: With horses, there is some effect from human selection, too. Racing & show breeds tend to have thin lower legs, draft horses & working breeds have proportionately thicker ones. My first horse, a thorobred/arab mix, had legs about as thick as my wrists (granted, I'm a fairly muscular guy); my current mustang, about the same height & weight, has legs about twice as thick.
The following is multiple choice question (with options) to answer.
If a bear has thick legs fur, then | [
"her mom was very old",
"his hair is blonde",
"her arms are wide",
"his ancestors had the same"
] | D | the thickness of the parts of an organism is an inherited characteristic |
OpenBookQA | OpenBookQA-2782 | zoology, ornithology, ethology, behaviour
Title: Crow branch pecking behaviour I was walking through a small park when two crows started cawing at me, and followed me, flying from tree-to-tree as I walked. I speculate that this is a territorial or protective behaviour, but what I found different was the crows were violently pecking the branches nearby them. I have no memories coming to mind of seeing this behaviour beforehand. I speculate that this behaviour could be threat displays, but a quick search on Google did not reveal to me any authoritative studies on this phenomenon. I'd appreciate more information and sources.
This question has been added as a casual observation on iNaturalist. This is a good question. This type of behavior -- pecking at a branch, wiping the side of the beak on a branch, pulling off twigs and dropping them, or knocking off pieces of bark -- is quite common among many corvid species, particularly when they are interrupted by something or someone that they might consider a threat. This includes not only potential predators but also potentially hostile conspecifics.
It is typically considered to be a form of displacement behavior. The concept of displacement behavior, from classical ethology, posits that when an animal experiences two conflicting drives to do two different things, it doesn't know which to do and does a third thing instead to dissipate the drive or anxiety. For branch-pecking in crows, see E.g Kilham and Waltermire 1990 Ch. 12.
Referece: Kilham, L., & Waltermire, J. (1990). The American crow and the common raven. Texas A&M University Press.
The following is multiple choice question (with options) to answer.
Which of these things would cause more racoons to hang out nearby? | [
"shooting them as they come",
"cutting their hair at night",
"leaving lids off garbage cans",
"putting garbage cans inside the garage"
] | C | raccoons eat waste |
OpenBookQA | OpenBookQA-2783 | electromagnetism, geophysics, geomagnetism
Title: Why is modelling the Earth as having geomagnetic poles useful? I'm reading about geomagnetic poles and wondering what their signifcance is. It seems one (and perhaps the main) purpose of using this type of model is for understanding the aggregation of magnetic particles from outside of earth. I feel as though I'm missing a step as to why this model is used, surely the magnetic particles from space still experience the irregular magnetic field of earth?
My guesses from the reading I've done so far are that:
At a great distance, the magnetic particles do actually experience equivalent attraction as though the Earth had a bar magnet that gave it its geomagnetic poles.
Over some time period, and over a number of particles the force experienced by all particles averages to what would be experienced if the Earth had a bar magnet that gave it its geomagnetic poles.
The following is multiple choice question (with options) to answer.
If Earth has poles that are magnetic | [
"needles will glow in the dark because of them",
"needles will stab them",
"some poles will be radioactive",
"needles aim that way"
] | D | a compass 's needle lines up with Earth 's magnetic poles |
OpenBookQA | OpenBookQA-2784 | Conversely, suppose $n=2^m\cdot \gcd(a_0,b_0,c_0)$. We can solve the puzzle as follows. If the current state is $\{a,b,c\}$, write $a=2^x a'$, $b=2^y b'$, $c=2^z c'$, where $a'$, $b'$, and $c'$ are odd. The condition on $n$ implies that either $a=b=c$, or that of the three numbers $x$, $y$, and $z$, two will be equal and the third will be larger.
Reordering if necessary, we can assume $x=y<z$ and that $a\leq b$. If $a< b$, replace $\{a,b,c\}$ by $\{2a,b-a,c\}$ and repeat the process. If $a=b$, replace $\{a,b,c\}$ by $\{2a,b,c-a\}$ (if $a<c$) or $\{a-c,b,2c\}$ (if $a>c$) and repeat the process. This will eventually terminate with all three bowls having the same number of peas. The reason this terminates is that if $\{a,b,c\}$ is replaced by $\{2a,b-a,c\}$, then the values of $x$ and $y$ increase by at least one. The replacement with $\{2a,b,c-a\}$ or $\{a-c,b,2c\}$ cannot happen twice in a row, and the size of $x$, $y$, and $z$ must remain bounded.
The following is multiple choice question (with options) to answer.
If peas and carrots are planted alternately, | [
"fields are useless",
"dirt is refreshed",
"sand is dried",
"water is poisoned"
] | B | crop rotation renews soil |
OpenBookQA | OpenBookQA-2785 | 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.
Consumers eat other what? | [
"oxygen",
"animal toys",
"rays",
"weaker bugs"
] | D | consumers eat other organisms |
OpenBookQA | OpenBookQA-2786 | earth-history, mass-extinction, geobiology, evolution, ecology
Title: Why haven't weeds overtaken the entire planet? Given how rapidly weed plants spread and grow, choking out all other plant life, how come after millions of years we haven't ended with forests full of thistle or pokeweed, as opposed to pines or oak trees? A weed is just a plant where you do not want it. Totally a matter of context. Tumbleweeds are non-native, introduced centuries ago. I assume you mean the invasive species of plants that have been spread by humans and are disrupting ecologies throughout most of the world
Until recently, these plants we consider weeds were limited in their range to home environments simply by geographic barriers and surrounding unfriendly environments. And the natural consumers, parasites and competitors in the home environments had adjusted to these plants and kept them in check.
When non-native plants are introduced into a new environment by humans, most of them do not thrive, but occasionally a plant is wildly successful. Eventually the potential consumers, parasites and competitors in that new environment will adjust through evolution. But the tragedy is that many or most of the original species will be destroyed before that balance is restored in a new, way more simplified form. The landscape itself may be totally changed. Removal of a key original species can cause great change too: How Wolves Change Rivers.
Not only will many ecologies be reduced to much simpler versions, even if they eventually conquer the invasive plant, those simplified ecologies will closely resemble each other, if their geography is similar, even if on the other side of the world. If humans were to totally stop transplanting invasive species (collapse of civilization?), diversity would return after millions of years. We know this from Extinction Events.
So to answer you question, weeds before human intervention generally did not take over in their home environments because the potential weeds and their natural consumers, parasites and competitors all evolved together in a quasi-equilibrium. Now, however, most ecologies throughout the world are out of equilibrium because of environmental change and/or invasive species. This will inevitably lead to simplified, usually less robust, weedy ecologies throughout the world. That reduction in diversity might as well be considered a permanent situation compared to the timescale of civilization.
The following is multiple choice question (with options) to answer.
A yard can become a changed environment when | [
"crows show up",
"humans see it",
"worms live there",
"vegetables are farmed"
] | D | farming changes the environment |
OpenBookQA | OpenBookQA-2787 | thermodynamics, combustion
Title: Recovering mechanical energy from natural gas water boiler Is there any heat energy lost to the mechanical force of pushing a piston in a combustion engine?
In other words, would a natural gas burning as a flame produce more heat than the same amount of natural gas that was burned when driving a combustion engine?
The context of this question is around fuel efficiency of natural gas water boilers.
My current understanding is that a naked natural gas flame is burning inside the unit, and heats water that is contained within a series of pipes, which in turn is cooled in a heat exchanger, and that same heat exchanger heats the incoming cool water.
I'm wondering, would if it make any sense at all to burn that natural gas inside a combustion engine and use the heat of the combustion engine used to heat the water to the same extent as a naked flame.
More generally my goal is to solve the question, can we heat water the same extent by burning the same amount of natural gas and get free mechanical energy?
Thanks Check out combined heat and power systems... generates electricity and makes use of the waste heat to heat water - but is only really efficient when there is sufficient hot water demand ie heating load.
The following is multiple choice question (with options) to answer.
You can produce what by burning natural gas? | [
"snow",
"a warmer room",
"oxygen",
"water"
] | B | natural gas is a source of heat by burning |
OpenBookQA | OpenBookQA-2788 | Best Japanese Brown Rice, Air Fryer Burgers And Fries, østfold University College Vacancies, Band T-shirts Walmart, How To Become An Anglican Priest, Too Much Fennel Taste, Porter Cable Circular Saw Cordless, Utmb My Chart, Iams Large Breed Dog Food Nutrition Facts,
The following is multiple choice question (with options) to answer.
Chewying and swallowing a steak | [
"serves it hot",
"breaks it down",
"losses energy",
"dies"
] | B | break down means change from a whole into pieces |
OpenBookQA | OpenBookQA-2789 | thermodynamics
Based on this page in a “Blaze” book, my six year old asked “which would win?” between water and lava. On further investigation, we refined the question to: which would turn solid first in similar conditions, a liter of room temperature water or a liter of volcanic lava? You've got the right idea — you want to simplify the problem — but I don't think you're using quite the right simplification. Take a look at the book's set-up of the situation, and ask yourself how the water is stopping the lava. You'll see the idea is that we're using liquid water, not ice, to solidify the lava.
So your question should really be: How much heat do we need to absorb from a liter of lava to turn it into a solid, and how much heat can a liter of water at room temperature absorb before it turns to steam? If the latter is larger than the former, then a liter of water can cool a liter of lava to the point where it solidifies before the water all changes into steam.
[I'm using "heat" when I should really be using "thermal energy", but this is for a $6$ y.o., so I'm keeping it simple.]
First, let's do the calculation for water. Here (since it's for a $6$ y.o.), I'm not going to show all the steps in the calculations:
Energy to heat $\pu{1 L}$ liquid water at room temp ($25 \,\pu{^{\circ}C}$ ) to $100 \,\pu{^{\circ}C}$ = $\pu{75 kcal}$
Energy to turn $\pu{1 L}$ liquid water to steam at $100 \,\pu{^{\circ}C}$ = $\pu{533 kcal}$
Total = $\pu{608 kcal}$
According to https://en.wikipedia.org/wiki/Lava, lava is typically $700 \,\pu{^{\circ}C}$ to $1200 \,\pu{^{\circ}C}$, so let's call it $1000 \,\pu{^{\circ}C}$.
The following is multiple choice question (with options) to answer.
What is the source of cooling that turns lava into land? | [
"seawater",
"refrigerators",
"air conditioning",
"glaciers"
] | A | new land can be formed by volcanoes erupting by lava cooling |
OpenBookQA | OpenBookQA-2790 | human-biology, cancer, medicine
Title: Why are only few cigarette smokers prone to cancer? It's tacit that only a few populace of smokers get cancer. What spares the others from it or what specifically cause cancer in those populace? See this Washington Post Article Cigarette smokers are most certainly prone to cancer. See Cecil Medicine, Chapter 183, on the epidemiology of cancer, exposure to tobacco is the most important environmental risk factor for cancer development, at least in the US:
Exposure to tobacco is the single largest cause of cancer in the United States... All forms of tobacco can cause cancer. Cigarette smoking causes cancer of the lip, oral cavity, nasal cavity, paranasal sinuses, pharynx (nasal, oral, and hypopharnyx), larynx, lung, esophagus (squamous cell and adenocarcinoma), stomach, colorectum, pancreas, liver, kidney (adenocarcinoma and renal pelvis), urinary bladder, uterine cervix, and myeloid leukemia.
Cancer may be identified or the cause of death in fewer smokers than might be expected, though, because smoking is an even greater risk factor for cardiovascular disease, and death due to cardiovascular disease.
Cancer is an unlikely phenomenon in an individual cell, but becomes more likely at the organism level, and even more likely over time. Though tobacco may be the most important environmental risk factor for cancer, age is actually a stronger predictor of cancer (see again, Cecil Chapter 183. Autopsy studies give us a quite remarkable example, this one shows incidental prostate cancer in nearly 60% of men over 80 who died from other causes. That figure is not out of the ordinary. Live long enough and you are likely to develop cancer.
Death due to heart disease may account for the lower than expected rates of cancer diagnoses and deaths in smokers. Nothing prevents cancer as well as dying from something else. And as discussed in the blog in the Washington Post you linked to, up to 2/3 of smokers die from smoking related causes
The following is multiple choice question (with options) to answer.
Smoking can also effect what besides themselves | [
"wizards",
"space",
"Jonny and Susie",
"unicorns"
] | C | smoking causes direct damage to the lungs |
OpenBookQA | OpenBookQA-2791 | 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.
Erosion can | [
"Give me a hair cut",
"Create a beautiful painting",
"turn a statue to dust",
"Clean my car windows"
] | C | wind causes erosion |
OpenBookQA | OpenBookQA-2792 | theoretical-biology, hematology, red-blood-cell
**As an intern, I once had the very sorrowful experience of admitting an healthy appearing, exuberant 4 year old child to the pediatric surgical service. The only presenting symptom was that the child started squatting during exertion (not good), and on exam, had a murmur which was caused by aortic stenosis. This was long before imaging studies were as sophisticated as they are now. The pediatric cardiac surgeon took him to the operating room (OR) to replace the valve, but there was so much atherosclerotic aortic damage that there was no healthy tissue which could hold sutures in place. The child died in the OR. I don't know what would have been done today, but had the child stayed home, they might have had a couple more years with the parents, who hoped for an uneventful procedure. So the exercise involved in this answer was fun, but the memory it brought back is still quite sad.
The following is multiple choice question (with options) to answer.
Which is likeliest to be torn by a small child | [
"foil",
"wood",
"steel",
"oil"
] | A | tearing means changing a whole into pieces |
OpenBookQA | OpenBookQA-2793 | entomology
Title: What is the name of this tiny creature? It looks like a tiny piece of moving cotton? By chance, I saw this tiny insect on my bag a few days ago in Sydney. Am I the first person who has pinpointed this animal?! If not can you please let me know its name? From your image, it looks like it might be a woolly aphid. I just did a bit of cursory research, and it looks like they're often described as floating pieces of fluff, that seem to wander instead of directly heading somewhere. The fluff on their back is actually wax produced as a defense mechanism from predators and the like. I hope this is what you were looking for!
The following is multiple choice question (with options) to answer.
Organic mass is gained in the earth by insect | [
"JDZ clones",
"mushroom farmers",
"garbage eaters",
"trash removers"
] | C | decomposition increases amount of organic matter in soil |
OpenBookQA | OpenBookQA-2794 | sleep, hearing, perception
Title: What is the term for awareness of or inclusion of real sounds within a dream? I fell asleep while listening to a podcast, and I am sure I was dreaming but I could also still hear the podcast.
The podcast played an important role in the dream, I was searching for the source of the voice, wondering if others in the dream could hear the same voice. I started to feel a bit panicky and woke up as the podcast also happened to end. I rewound the show and confirmed that it was all there, exactly as I had heard in my dream!
I would like to read more about this type of experience, but I am having trouble finding the right words to search. Is there a name for this phenomenon? Is there anything that contributes to experiences like these? I know it wasn't lucid dreaming, because I wasn't aware of being asleep. I think I found a good expression : "sensory incorporation in dreams"
https://www.psychologytoday.com/blog/dream-factory/201409/sensory-incorporation-in-dreams
It doesn't seem reflected in a Google Scholar search however, and I don't find a consistent terminology in the papers that do seem to be about the subject. That article can be a good starting point though.
EDIT: other good one: "influence of external stimuli on dreams".
https://journals.ub.uni-heidelberg.de/index.php/IJoDR/article/view/15754
The following is multiple choice question (with options) to answer.
one's ability to hear their name being called across the room indicates the presence of | [
"gas in the stove",
"water in the walls",
"atmosphere in the space",
"water in the ears"
] | C | sound can travel through air |
OpenBookQA | OpenBookQA-2795 | special-relativity
$$ t' = (t-v\cdot x/c^2)/sqrt(1-v^2/c^2) $$
It's the $v\cdot x$ term in the numerator that causes the mischief here. In the runner's frame the more distant event (larger $x$) happens earlier. The far door is closed first. It opens before she gets there, and the near door closes behind her. Safe again — either way you look at it, provided you remember that simultaneity is not a constant of physics.
The following is multiple choice question (with options) to answer.
which of these could result in a person reaching their destination late? | [
"a clear road path",
"a dry clear road",
"a road full of ice",
"a road without hills"
] | C | skidding causes speed to decrease |
OpenBookQA | OpenBookQA-2796 | algorithms, reference-request, distributed-systems
I'm not aware of any literature on this and I don't particularly see any reason to expect there to be any. It's a very specific set of requirements, and it looks to me like the resulting task is either trivial or impossible to solve. Those usually aren't the kind of problems that tend to be studied in the literature. Perhaps you might be interested in persistent data structures, but that's just a fancy way of storing the entire history of events, which you said you want to do; and you don't need a fancy data structure to do that in your particular situation.
The following is multiple choice question (with options) to answer.
A resource that can be endlessly retrieved is | [
"knobs",
"bricks",
"panels",
"droplets"
] | D | water is a renewable resource |
OpenBookQA | OpenBookQA-2797 | zoology, pathology, herpetology
Title: How do pet gecko lizards pose a health risk? Does having gecko lizards living in your house pose any health risk? If you're referring to keeping geckos as pets, like all reptiles, amphibians and birds, they come with a small but finite risk of contracting salmonellosis. Having said this, the infection is easy to avoid if you maintain basic hygiene.
On a personal note, I know dozens (perhaps hundreds) of people who keep or have kept reptiles as pets and have yet to meet anyone who contracted salmonellosis. Basically, if you wash your hands after touching the gecko, keep it away from food preparation areas and don't put the lizard in your mouth, you should be fine.
If you're talking about geckos living free in your home, as is common in many tropical places, I have never heard of any health risks associated with them. If anything, I would think that the geckos would reduce health risks by eating insects such as cockroaches and mosquitoes that are prominent disease carriers.
The following is multiple choice question (with options) to answer.
To keep a pet salamander healthy what would come in handy? | [
"live house flies",
"a dog",
"plant fertilizer",
"snakes"
] | A | a salamander eats insects |
OpenBookQA | OpenBookQA-2798 | spacetime, velocity, space-expansion, dark-energy, galaxy-clusters
Also, I found this Forbes article by one of the authors to be particularly good at explaining in layman's terms the question of what a "repeller" means, when gravity is purely attractive.
The concept of a low-mass region of mostly void pushing things struck me as peculiar until I read that and realized the current thinking (per the new work) wasn't so much that the repeller is truly "pushing" (a violation of how gravity is understood to work) but rather as incrementally removing the resistance to the pulling, that amounts to a similar (and synergistic!) outcome to the more familiar "pulling" we see from objects of mass (orderly movement).
The following is multiple choice question (with options) to answer.
An unseen force tugs at celestial bodies giving them | [
"shape",
"luster",
"a trajectory",
"color"
] | C | gravity causes orbits |
OpenBookQA | OpenBookQA-2799 | species-identification, marine-biology
Title: help identify this fish
I came across this washed up fish in Panama City, Florida in November 2015. I'm guessing it's a puffer fish but I can't find anything like it online.
Thanks. This is a kind of trunkfish. (They have different names, this could be a smooth or spotted trunkfish.). It's really a lovely and comical little fish when observed alive in coral reefs. It has the ability to change its coloration depending on whether it's excited or calm, or to minimize its contrast to the background. It is related to puffer fish.
It has a boxy, triangular body shape, and propels itself with relatively tiny, delicate fins. Like pufferfish, they are toxin producers.
In death, the body shape and coloration are different, of course. Never saw a dead one before; sad. The juveniles are adorable:
Members of this family occur in a variety of different colors, and are notable for the hexagonal or "honeycomb" patterns on their skin. - Wikipedia
The following is multiple choice question (with options) to answer.
Catfish are what | [
"cannibals",
"fairies",
"grapes",
"unicorns"
] | A | predators eat prey |
OpenBookQA | OpenBookQA-2800 | beam
all the distances are positive (everything is either above or to the right of $A$)
the horizontal distributed load is positive
the vertical loads are negative
$F_{E,y}$ is whatever it will be (positive, in our case)
When calculating the moment due to vertical forces, the sign is positive
When calculating the moment due to horizontal forces, the sign is negative
The following is multiple choice question (with options) to answer.
If a pull is strong somewhere, it likely has | [
"snakes",
"magnitude",
"water",
"frames"
] | B | gravitational force causes objects that have mass to be pulled down on a planet |
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