source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-3101 | polymers, molecular-structure
References:
Rice, E. W. The preparation of formazin standards for nephelometry. Analytica Chimica Acta 1976, 87 (1), 251–253.
Ziegler, A. Issues Related to Use of Turbidity Measurements as a Surrogate for Suspended Sediment. Turbidity and Other Sediment Surrogates Workshop; Reno, NV, USA, 2002.
Kaur, N.; Kishore, D. An Insight into Hexamethylenetetramine: A Versatile Reagent in Organic Synthesis. J. Iran. Chem. Soc. 2013, 10 (6), 1193–1228.
Sadar, M. J. Stabilized Formazin Composition. US Patent 5,777,011, July 1998.
Mashima, M. The Infrared Absorption Spectra of the Condensation Products of Formaldehyde with Hydrazine. Bull. Chem. Soc. Jpn. 1966, 39 (3), 504–506.
Bondybey, V. E.; Nibler, J. W. Infrared and Raman Spectra of Formaldazine. Spectrochimica Acta Part A: Molecular Spectroscopy 1973, 29 (4), 645–658.
The following is multiple choice question (with options) to answer.
Sediment is a result of the process of | [
"running",
"jumping",
"magic",
"rain"
] | D | when a river floods , that river deposits sediment in flood plains |
OpenBookQA | OpenBookQA-3102 | ethology, sociality, animal-psychology
Title: Frogs stop croaking at same time I know frogs start croaking at the same time to attract a female.
Why do they all stop at the same time? Calling is a risky activity because it makes the frog conspicuous to predators. When calling in a group, the risk to any given individual is minimized to the point that the minimal risk is outweighed by the advantage of attracting a mate. However, a single frog calling on his own is assuming all of the predation risk. So, the frogs are playing a bit of game theory and when too few are calling simultaneously to make the risk worthwhile, they will all tend to stop.
The following is multiple choice question (with options) to answer.
An burrowing frog breaks through the mud after it's done | [
"slumbers for years",
"migrating",
"moving indoors",
"being exported"
] | A | when a hibernating frog emergest from mud , that frog has ended its hibernation |
OpenBookQA | OpenBookQA-3103 | plant-physiology
Title: Would a plant survive if it was watered using hard-water? Hard water is water with high mineral/salt content. I'm told that a potted plant watered with a salt solution dries out sooner or later. Is this true?
If so, would a plant survive if watered using hard-water? It would depend on the content of the hard-water. If the water contained heavier metals like lead or radioactive elements like tritium (Hydrogen-3), the plant would most likely die. Most land plants cannot survive when watered with massive amounts of salt water as the salt would absorb the water from the leaves.
The following is multiple choice question (with options) to answer.
Which of these items plays an integral role in the survival of many types of flora? | [
"bee",
"cat",
"dog",
"mouse"
] | A | A bee is a pollinating animal |
OpenBookQA | OpenBookQA-3104 | c++, strings, reinventing-the-wheel
void my_string::pop_back()
{
if (m_size == 0) return;
m_contents[m_size - 1] = '\0';
alloc.destroy(&m_contents + m_size);
//destroy old terminating zero
alloc.destroy(&m_contents + m_size + 1);
--m_size;
}
void my_string::push_back(char c)
{
if (m_space == 0) reserve(8);
else if (tot_size() == m_space) reserve(2 * m_space);
alloc.construct(&m_contents[size()], c);
alloc.construct(&m_contents[size() + 1], '\0');
++m_size;
}
my_string & my_string::operator+=(const my_string & rhs)
{
return insert(m_size, rhs.c_str());
}
my_string::~my_string()
{
cleanup();
}
std::ostream & operator<<(std::ostream & os, const my_string & rhs)
{
return os << rhs.c_str();
}
void my_string::cleanup()
{
for (int i = 0; i < tot_size(); ++i) alloc.destroy(&m_contents[i]);
alloc.deallocate(m_contents, m_space);
}
The following is multiple choice question (with options) to answer.
If a bass is returned to its home, it is placed in | [
"a brook",
"a field",
"a jungle",
"a coven"
] | A | a fish lives in water |
OpenBookQA | OpenBookQA-3105 | evolution, mycology
Title: Why are some fungi poisonous? There are many poisonous fungi in nature. For example Amanita Phalloides.
What reasons could a fungus need poison for? Some species, like venomous snakes, use poison to kill other species as prey. But what about fungi? I can't think of any purpose for poison in fungi. If poison has no real function in fungi shouldn't evolution get rid of it? The same reason some plants are poisonous: to stop animals from eating them.
The visible part of the fungus is called, rather misleadingly, the fruiting body. It exists to produce and spread spores and thus produce the next fungal generation. Getting eaten, rather obviously, inhibits its ability to do this. Being poisonous discourages animals from eating the fruiting body and thus permits it to complete its life cycle.
The following is multiple choice question (with options) to answer.
If you see a mushroom on an old decaying log, its because a mushroom is a decomposer, which gets its food from | [
"non-alive things",
"space",
"computers",
"the store"
] | A | dead organisms are the source of nutrients for decomposers |
OpenBookQA | OpenBookQA-3106 | reinforcement-learning, ai-design, control-theory
Without any proximity reward, you will rely on the wolf literally bumping into the rabbit through random behaviour, before it will have any data example that getting the vector between itself and the rabbit close to (0,0) is a good thing. You may need to have a relatively large capture radius, plus limit the area that the wolf (and eventually rabbit) can explore, in order to avoid very long sequences of random behaviour where nothing is learned initially.
The following is multiple choice question (with options) to answer.
If a dog is hunting for wild rabbit or birds, then | [
"it needs to drink",
"it can sense children nearby",
"it can tell where a victim is",
"it is wanting to play frisbee"
] | C | if two animals have the same food source then those two animals compete for food |
OpenBookQA | OpenBookQA-3107 | energy, fuel, environmental-chemistry
Title: Effect of coal and natural gas burning on particulate matter pollution I sometimes hear people talking about how we should replace coal burning plants with natural gas ones, to alleviate the case of particulate matter pollution. What exactly is the difference between coal fuel and natural gas that makes the latter seem "cleaner"?
At the same energy outcome, natural gas produces less carbon dioxide than coal. In a way, natural gas is half way between coal and hydrogen.
Coal produces smelly smoke, solid particles, sulfur dioxide and minor or trace heavy metal pollutants.
It is less known to common people, but power plants burning coal are more significant source of radioactive pollution than nuclear plants. This pollution is very diluted, but rather significant in absolute amount. Coal ash, used in past as a filler for some construction materials, has lead in some cases to significantly increased content of radium-226 in building walls. This radium is a product of long term decay of natural uranium. It further decays while producing radioactive gaseous radon-222, which is dangerous in long term inhalation because of lung cancer. As it stays in lungs as polonium-218 and its decay products.
See e.g. Uranium produced from coal ash
... the uranium concentration in the ash pile is about 150-180 parts per million, about 1/4th of the concentration often thought of as commercially viable for ISL[In Situ Leaching] mining. However, coal ash piles have some physical characteristics that might help overcome that disadvantage since they may be easier to drill and it might be easier to protect the local groundwater from contamination. ...
See Radon in building materials by Czech government agency for radiation protection.
The following is multiple choice question (with options) to answer.
Using less anthracite has a positive impact on the | [
"stock market",
"ecosystem",
"coal plants",
"electric companies"
] | B | conserving resources has a positive impact on the environment |
OpenBookQA | OpenBookQA-3108 | 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.
Over the lifetime of the planet hydro mechanical wearing will create a | [
"crevasse",
"ocean",
"drought",
"water park"
] | A | a canyon forming occurs over a period of millions of years |
OpenBookQA | OpenBookQA-3109 | 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 sign of the spring season could be | [
"hibernation",
"flip-flops",
"Christmas",
"heavy coats"
] | B | a new season occurs four times per year |
OpenBookQA | OpenBookQA-3110 | atmosphere, carbon-cycle
Title: For a tree over its entire existence, does it actually have a net negative effect on atmospheric CO2? A tree while alive converts CO2 + water -> carbohydrates + O2. However, once the tree dies, it decays, releasing CO2 back into the atmosphere. My question is, over an individual tree's overall existence, does a tree actually contribute to a reduction in atmospheric CO2?
I'm aware there's other pathways a tree could end up as a more long term carbon store (carbonaceous rocks), but mostly interested in if a tree were to die and fall in a forest, decay in 50-150 years, would it have contributed to a net reduction in CO2, or does a tree typically act as more of a temporary 100+ year store of CO2? A brief review of recent non-paywalled available literature indicates that such an effect likely exists but that it is difficult to quantify based on currently available data.
Some amount of carbon from trees can be sequestered in the soil for periods time significantly longer than the typical above-ground decomposition time of organic matter, potentially for millennia. This clearly lengthens the carbon cycle time, but it is not clear to me whether this represents carbon storage, as there does not seem to be a well established minimum cut-off time for this. The primary source for soil-sequestered carbon are tree roots, with leaf litter constituting a secondary source.
The following paper (preprint online) addresses the question in the specific context of agroforestry, i.e. cropland interspersed with trees. The paper notes multiple times that the processes involved in soil sequestration are not well understood and that quantitative measurements and estimates vary widely, as one would expect based on differences in climatic and soil condition. Note on units: A Mg corresponds to a metric ton.
Klaus Lorenz and Rattan Lala, "Soil organic carbon sequestration in agroforestry systems. A review." Agronomy for Sustainable Development, Vol. 34, No. 2, April 2014, pp. 443-454.
The following is multiple choice question (with options) to answer.
Cutting down trees has a negative impact on what living in an ecosystem? | [
"disks",
"plans",
"stone shelves",
"critters"
] | D | cutting down trees has a negative impact on an organisms living in an ecosystem |
OpenBookQA | OpenBookQA-3111 | botany, marine-biology, salt
Title: Mangroves and desalination of sea water I am not an expert but I guess that mangroves (or some other plants that thrive in sea water) perform some kind of desalination to extract fresh water from sea water.
Is this true? If yes, What biological mechanisms are used to remove salt from sea water?
I am interested in any research about biological desalination. This paper might be of interest to you: https://advances.sciencemag.org/content/6/8/eaax5253.
The researchers created a synthetic mangrove that actually performs desalination, using the principles of natural mangroves.
The introduction has a good overview of the main ways mangroves desalinate saline water, namely:
Physical blockage by suberin within cells walls
Selective permeability of cell membranes in root
Negative pressure caused by evaporation that acts as hydraulic pressure to cause take-up of water by roots
All these combine to turn the mangrove into a kind of natural RO (reverse osmosis) machine.
The following is multiple choice question (with options) to answer.
Desalinating water from the what deals with removing salt? | [
"helps them out",
"rain from mountains",
"oceanic liquids",
"trees watered"
] | C | oceans contains most of earth 's water |
OpenBookQA | OpenBookQA-3112 | electromagnetism, computer
As for MRI scanners, there's a reason why the first and last thing they check, when you go and have an MRI scan, is that you have nothing potentially ferromagnetic on or in your body. The reason is that anything ferromagnetic that gets too close to an active MRI magnet is likely the get torn off your hands and violently slammed against the magnet. This has been known to happen to pretty much any wholly or partially ferromagnetic object you'd care to imagine, from wheelchairs, office chairs and floor polishers to scissors, oxygen bottles (which killed a small child) and even pistols (which, yes, went off when it hit the scanner).
So, let's imagine what'll happen to your hapless policeman, as he's walking towards the magnetized door carrying a stack of hard drives. The first thing he's likely to notice, while still several meters away, is that something's pulling at the drives he's carrying (since they have a lot of ferromagnetic metal in the casing, and even some pretty strong magnets inside). If he's not careful, the drives might slip out of his hands and fly through the air towards the door, slamming against the door jamb with enormous force (and, yes, likely getting pretty well wiped in the process).
The next thing he might notice, if that's not enough to make him stay well away from the door, is that the same force is also tugging at his badge, gun, zipper, belt buckle, the screwdriver in his pocket that he used to open the servers and extract the hard drives, and anything else metallic that he might have on him. If he's not careful, and keeps approaching the door, those items might either get pulled out of his pockets, or they might simply get drawn to the door and pull him along with them. If he's lucky, the only thing getting pinched between the door and the objects is his clothing. If he's not...
The following is multiple choice question (with options) to answer.
MRIs can make | [
"fillings dance",
"great yogurt",
"programs for assembly",
"a mess"
] | A | non-contact forces can affect objects that are not touching |
OpenBookQA | OpenBookQA-3113 | meteorology, hypothetical, water, geomythology, flooding
Title: Is a complete global flood physically possible on Earth? Genesis 7:11-20 presents an account of an event which, in 40 days, submerges the entire surface of the earth:
[On] the seventeenth day of the second month — on that day
all the springs of the great deep burst forth, and the
floodgates of the heavens were opened…
For forty days the flood kept coming on the earth… all the high
mountains under the entire heavens were covered. The waters rose
and covered the mountains to a depth of more than fifteen cubits
[6.86 m].
Based on this account, my questions are:
Given the amount of water on Earth (including all the water as liquid, solid, and gas, in all possible places: the atmosphere, the surface, and underground), is there enough water to flood the whole earth until ‘all the high mountains… were covered’?
What is the estimated rainfall intensity based on this description, and how intense is it in comparison with today’s rainfall intensity in tropical areas?
Regardless of the veracity or otherwise of the account, this makes for an interesting thought experiment. there is not enough existing water inside this geosystem IMO for such a thing to occur. Let's see these figures here:
One estimate of global water distribution
Oceans, Seas, & Bays 1,338,000,000 -- 96.54% of all water
this figure means that most of the existing water at the global scale is seawater. Sea floor is quite irregular, with some abyss like pits (ex: Mariana trench), up to low water in shallow sea near continents and islands (See figure). A variable topography overall
The following is multiple choice question (with options) to answer.
Where would more water fall from the sky yearly? | [
"inside of a mansion",
"a place where wild camels roam",
"a place where a lot of grass grows",
"on dark side of the moon"
] | C | a grassland environment receives more rainfall than a desert |
OpenBookQA | OpenBookQA-3114 | That would be a total of 5x30 + 3x40 + 2x60 = 390 plants (with an arbitrary factor that we'll set to 1 without loss of generality).
The amount of highbush is 5x30 = 150.
The amount of lowbush is 3x40 = 120.
The amount of hybrid is 2x60 = 120.
If the opossums didn't care, they would likely eat blueberries in this ratio (null hypothesis H0).
The total that we have observed the opossums to eat is 5% x 150 + 10% x 120 + 20% x 120 = 43.5 plants.
They eat 5% large, which a corresponding fraction of 5% x 150 / (5% x 150 + 10% x 120 + 20% x 120) = 17%
They eat 10% low for 10% x 120 / (5% x 150 + 10% x 120 + 20% x 120) = 28%
They eat 20% hybrid for 20% x 120 / (5% x 150 + 10% x 120 + 20% x 120) = 55%.
Checking... yes the total is 100%.
What we see is that the opossums prefer hybrid by far.
Small blueberries are their second choice.
Last edited:
#### anemone
##### MHB POTW Director
Staff member
Hi anemone!
What do you mean by the symbol E?
Anyway, you've found that the opossums eat 45.8% large and 54.2% small for a total of 100%.
But... what happened to the hybrid blueberries?
By the symbol E, I meant the blueberries (all 3 types of them) that are eaten by opossums...
That would be a total of 5x30 + 3x40 + 2x60 = 390 plants (with an arbitrary factor that we'll set to 1 without loss of generality).
The amount of highbush is 5x30 = 150.
The amount of lowbush is 3x40 = 120.
The amount of hybrid is 2x60 = 120.
If the opossums didn't care, they would likely eat blueberries in this ratio (null hypothesis H0).
The following is multiple choice question (with options) to answer.
If a deer eats a berry plant, the plant eats | [
"a berry juice slurry",
"large slices of meat",
"its self created nutriment",
"small bugs that glow"
] | C | green plants provide food for consumers by performing photosynthesis |
OpenBookQA | OpenBookQA-3115 | php, object-oriented, classes
$FirstRockBand->displayMembers();
//echo count($FirstRockBand->badArray);
if (count($FirstRockBand->badArray) > 0){
$FirstRockBand->sorryReject("Sorry", "you didn't make it in.");
echo "<br /><br /> The rejected members have started their own group: " . $SecondRockBand->name . "<br /><br />";
$SecondRockBand = new Band("Death Metal", "Sideshow Hubris");
$RockBands = array(
$FirstRockBand,
$SecondRockBand
);
foreach($FirstRockBand->badArray as $k => $v){
foreach($v as $inst => $member){
$SecondRockBand->recruitMembers($inst, $member);
}
}
//echo '<div style = "background-color: 00FFFF">';
$SecondRockBand->displayMembers();
//echo "</div>";
//Battle of the Bands! Scales tipped on the side that has more members. Need to work on the whole talent thing.
$FirstRockBand->battle($SecondRockBand, "blew the crowd away!");
}
The following is multiple choice question (with options) to answer.
Where do some Metallica band members live? | [
"trees",
"space",
"underwater",
"houses"
] | D | some humans live in houses |
OpenBookQA | OpenBookQA-3116 | sexual-reproduction
So when it's not maintained -- when there's no selection pressure on two populations -- inevitably there will be genetic drift that will randomly disrupt this fine-tuned system. If a population of, say, voles is isolated on an island, they will continue to have pressure to be able to interbreed with other voles on the island, but if they can't interbreed with those on the mainland there won't be any consequences, and so over long enough time they'll drift and lose that ability -- just as many apes, not suffering any consequences from not synthesizing vitamin C, gradually lost that ability from random drift.
There's another side to it. Two populations in the same location may be positively selected to not be able to interbreed. Think about two groups of finches, one with small fine beaks that eat tiny seeds deep inside pine cones, and one with heavy beaks that crush and eat thick-shelled nuts. They each do fine, but they can interbreed and produce offspring that have intermediate beaks -- too thick to reach the fine seeds that one parent eats, but too delicate to crush the nuts that the other parent eats. Those intermediate offspring will die off, and both parents will have wasted their resources raising them. Both parents would be better off not breeding with each other, but only breeding with their own kind to produce specialized and efficient offspring. There is now selection pressure on the birds to recognize their own kind (perhaps through songs or mating displays) and ultimately to be inter-sterile, so they never waste resources on the un-fit offspring. There's a gradation of separation over time, in which the different populations become more and more distinct. Eventually, at some arbitrary point, humans start calling them "species", but that's just us, not biology.
"Species" is an important concept, but it's not special in evolution; speciation is just one aspect of natural selection, there's nothing magical about it.
The following is multiple choice question (with options) to answer.
In order for a species to continue, constant mating is required to | [
"Make TVs",
"ice cream",
"make a cake",
"make babies"
] | D | reproduction produces offspring |
OpenBookQA | OpenBookQA-3117 | motor, hardware, dc
$$ P = \tau \times \omega$$
Mechanical power is the product of torque and angular velocity. We can calculate that for the given mechanical power of $800W$, with the target velocity of $18.45 rpm$ you will have $43.4 Nm$ of Torque available at the wheel axis. Now we have assumed $150mm$ wheel diameter, so the radius of the wheel is $75mm$. $43.4 Nm$ on a distance of $75mm$ produces $578.6 N$ of force. This is the maximum force that you can get at your wheels.
$40\%$ slope translates to $21.8 \deg$. From this we can deduce, that the sin component of your gravitational force cannot exceed $578 N$. At the limit
$$F= m * g * sin(21.8 \deg)$$
$ 578.6 N = m kg \times 9.81 m/s^2 \times 0.189$. So your absolute maximum weight from a static perspective is about $312 kg$.
Please note that this is the max weight you can move at $5km/h$ with a $1kW$ motor at a 40% slope on a perfectly flat terrain and it does not mean that with this weight your system can actually accelerate to this velocity. The more you are under this weight limit the more dynamic performance your system will have! Furthermore there might be some fictions forces to consider from the 140 cc engine that will further reduce the dynamic performance.
For the power capacity, if you put the two batteries in series, you get 24V and 18 Ah. This will mean that your batteries will be able to power your system under full load, for $18Ah / 43A = 0.41h$. So about 24 minutes of fun.
The following is multiple choice question (with options) to answer.
A battery operated vehicle requires everything but | [
"electricity",
"ions",
"petroleum",
"charging"
] | C | an electric car uses less gasoline than a regular car |
OpenBookQA | OpenBookQA-3118 | thermodynamics, thermal-radiation, physical-chemistry, biophysics, solar-cells
Title: Extreme life - energy source for living tens of kilometers underground? Living cells were found up to at least 12 miles underground (article), and in other extreme places (BBC survey article), for which beside the problem of just surviving in such extreme conditions, a basic physics thermodynamical question is: what energy source it is based on?
And in such extreme temperatures there is needed a lot of energy just to fight 2nd law of thermodynamics - actively protect cell's structures against thermalization.
Such energy source needs to be relatively stable for past billions of years - what seems to exclude chemical energy sources (?)
One stable energy source in such high temperatures are thermal IR photons, and thermophotovoltaics is generally able to harvest energy from them. However, cell living in such extreme conditions would rather have the same temperature, hence 2nd law seem to forbid harvesting energy from such IR photons? Chemical.
As the Wikipedia entry on Lithoautotroph puts it (restricting ourselves to the deep underground forms):
derives energy from reduced compounds of mineral origin
which they do through inorganic oxidation (see, e.g., Lessons from the Genome of a Lithoautotroph: Making Biomass from Almost Nothing) or other reactions, such as the reaction of formate (HCOO-) and water, to form bicarbonate and hydrogen (Extremophile microbes survive only on energy from formate oxidation).
The following is multiple choice question (with options) to answer.
energy is required for survival, and this is primarily delivered by | [
"the moon shining at night",
"the fifth planet from the sun",
"the closest star to our planet",
"the vast ocean body"
] | C | the sun is the source of energy for life on Earth |
OpenBookQA | OpenBookQA-3119 | temperature, light, heat
Title: Why does sunburn cause fever? Today I found out that sunburns can cause fever.
What I don't understand is how/why? In my understanding fever is the side effect of an immune reaction against an intruder, mainly bacteria (though I admit I can be wrong).
Google searches like "can sunburn cause fever" only bring up that it is possible, but not why. Here is a good article on the topic.
https://www.nlm.nih.gov/medlineplus/ency/article/003227.htm
But it's most likely due to the fact that a sun burn is an actual burn on the skin that can cause inflammation, inflammation can in turn cause fever. Also having a really bad sunburn can open you up more to the possibilities of skin infections. If this happens then once again you might get a fever due to infection. If you really want to find out more on the cause of fever after sunburn you need to examine the pathophysiology of fever and why fever happens. I bet my money on fever due to skin inflammation after a sunburn, I guess the real question would be why does inflammation cause fever since sunburn = skin inflammation
Here is a good article
http://antranik.org/inflammation-and-the-pathophysiology-of-fever/
The following is multiple choice question (with options) to answer.
A girl with a burn scar on her arm was most likely | [
"in a swimming pool",
"in a safe space",
"near a running kiln",
"protected from any injury"
] | C | if a body part was burned then that body part was exposed to a lot of heat energy |
OpenBookQA | OpenBookQA-3120 | newtonian-mechanics, forces, fluid-dynamics
We instead make use of the fact that air is far less dense than water for a given volume. Water molecules also exhibit hydrogen bonding, a significant intermolecular attractive force. In accordance with the equation, we find that water exerts a much larger viscous force than air because of it's higher coefficient of viscosity
In accordance with Newton's Second Law, the resulting acceleration reduces, making it "harder" to move objects using the same constant force. $$ F - F_v = ma_x$$
This assumption is only justified when the flow is laminar. For fluids with higher values of the Reynold Number, this viscous force becomes less dominant, because the flow becomes turbulent (Thanks @Rick for pointing this out)
The force of drag is a model of resistive force for an object moving through a fluid. It is given by $$R = \frac{1}{2}D\rho Av^2$$ where $D$ is the drag coefficient, and A is the cross sectional area of the moving object measured in a plane perpendicular to its velocity.
This resistive force, clearly increases with the square of the velocity, and is bound to play a dominating role when you push through a fluid (like in your example). Once again, you can use Newton's second law to show how this makes it "harder" to move through:
$$F - R = m. \frac{dv_x}{dt}$$
For reference, the coefficient of viscosity for water is $8.90 × 10^{-4} $ Pa.s and for air is $18.1 × 10^{-6}$ Pa.s
Hope this helps.
The following is multiple choice question (with options) to answer.
The force required to swim through ocean water is greater than the force needed to swim in a heated pool because | [
"pool water is usually cooler than ocean water",
"pool waves carry more turbulence than ocean waves",
"pool water has less mass and density than saltwater",
"saltwater has less mass and density than pool water"
] | C | as the mass of an object increases , the force required to push that object will increase |
OpenBookQA | OpenBookQA-3121 | 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.
During what period of the Earth cycle would you see someone having a picnic outside? | [
"Day",
"Night",
"Extinction",
"Ice Age"
] | A | cycles of day and night occur once per day |
OpenBookQA | OpenBookQA-3122 | # Two screws are inspected and the first is found to be good. What is the probability that the second is also good
#### Ram123
##### New member
Question: All the screws in a machine come from the same factory but it is as likely to be from A as from factory B. The percentage of defective screws is 5% from A and 1% from B. Two screws are inspected and the first is found to be good. What is the probability that the second is also good?
----------------------------------------------------------------------------------------------------
My attempt:
G1: First screw is good. G2: Second screw is good
G1A: First screw comes from A. G1B: First screw comes from B
G2A: Second screw comes from A. G2B: Second screw comes from B
P(G1A)=1/2, P(G2A)=1/2, P(G1B)=1/2, P(G2B)=1/2
P(G1A $\cap$ G2A)=P(G1B $\cap$ G2B)=P(G1A $\cap$ G2B)=P(G1B $\cap$ G2A)=1/2*1/2=1/4
Now,
P(G1)=P(G1|G1A)P(G1A)+P(G1|G1B)P(G1B)
The following is multiple choice question (with options) to answer.
If a screwdriver is bought from a high end store known for high quality, it will most likely end up | [
"falling apart quite fast",
"breaking in half immediately",
"with rotting wood this week",
"passed down from parent to child"
] | D | as the time a tool lasts increases , the number of tools discarded will decrease |
OpenBookQA | OpenBookQA-3123 | thermodynamics, evaporation, gas, liquid-state
On the water surface, knowing the temperature, we can estimate the vapor pressure and vapor mixture fraction. Then there will be an diffusion process for the water vapor to move out and for the ambient air to move in. Because the water surface doesn't allow the air to further move, a circulation forms. When the water vapor moves out, the water vapor pressure drops, so more liquid water evaporates to fill up the loss of water vapor. The evaporation associates latent heat so water surface area temperature drops (you may see dew on the bowl wall). Then a heat transfer process starts which may initiate water circulation as well.
As this is complex, doing test might be a quick way to get the K value if you assume it is a constant, which is questionable.
The following is multiple choice question (with options) to answer.
A horse is outside alone in the middle of summer on a sunny day in a desert. The horse is getting wet. The wetness is coming from | [
"orange juice",
"sunshine",
"rain",
"sweat glands"
] | D | sweat is used for adjusting to hot temperatures by some animals |
OpenBookQA | OpenBookQA-3124 | electromagnetism, electricity, electrons, atoms, voltage
1Actually, electrons are also small magnets themselves (they have an instrisic quantum-mechanical spin) and therefore are attracted to inhomogenic magnetic fields, but that's quite another issue.
2Actually, it would... but that's mostly relevant in the high-frequency-regime, i.e. bound electrons that jiggle back and forth very quickly.
The following is multiple choice question (with options) to answer.
What would be more attracted to a magnet? | [
"wood",
"A dog",
"a cloud",
"A zipper"
] | D | if a magnet is attracted to a metal then that magnet will stick to that metal |
OpenBookQA | OpenBookQA-3125 | The largest it can be is actually also the smallest it can be. In fact, if the numbers 1 through $n$ are written and the same process followed, the end result will be $(n+1)! - 1$ no matter what order you combine numbers.
Let's take a smaller set, just $\{a, b, c\}$, to see why. If you group $a$ and $b$ first, you'll end up with $$(ab+a+b)c+(ab+a+b)+c=a+b+c+ab+ac+bc+abc$$ If you group $b$ and $c$ first, you get $$(bc+b+c)a+(bc+b+c)+a=a+b+c+ab+ac+bc+abc$$ And just for completeness, grouping $a$ and $c$ first gives $$(ac+a+c)b+(ac+a+c)+b=a+b+c+ab+ac+bc+abc$$ At the end of the $n$ numbers, you will always end up with the sum of the individual numbers, plus the sum of the products of the numbers taken 2 at a time, plus the sum of the products taken 3 at a time, all the way up to the product of all the numbers. If you added 1 to the final sum, you could factor the final result into $(a+1)(b+1)(c+1)...$ giving $(n+1)!$ in this case.
Similarly, a starting list of the number $k$ written $n$ times will result in $(k+1)^n-1$.
The following is multiple choice question (with options) to answer.
Which of these supports an item that works together in large numbers and is greater than the sum of its parts? | [
"car",
"membrane",
"fire",
"truck"
] | B | the cell membrane provides support for a cell |
OpenBookQA | OpenBookQA-3126 | entomology, biophysics, hearing
$^1$ Bennet-Clark and Young, The Role of the Tymbal in Cicada Sound Production, J. of Experimental Biol. (1995) 198, 1001-1019.
$^{2}$ The frequency of cicadas is variable, mostly on the order of 10kHz but occasionally very low (< 1kHz), mostly due to body size. See this article.
$^3$ Sound--essentially a compression wave--diminishes with distance. So when the Wiki article on noise levels compares noise levels it includes the distance from the object. For example, 100 db (comparable to the cicada) is the level of noise associated with a jack-hammer at 1 meter away.
$^4$ Audible range for humans is roughly 15 Hz-16000 Hz. As mentioned below, the dolphin can emit very intense high-pitched sounds that we don't hear at all, so the analogy to EM waves (higher frequency = higher energy) doesn't help predict perception. See Pfaff and Stecker, Loudness and Frequency Content of Noise in the Animal House, Lab. Animals (1976) 10, 111-117.
$^5$ M. Versluis, B. Schmitz, A von der Heydt & D. Lohse (2000). "How snapping shrimp snap: through cavitating bubbles". Science 289 (5487): 2114–2117.
$^6$ Bennet-Clark and Young, Short Communication, The Scaling of Song Frequency in Cicadas, J. Exp. Biol. 191, 291-294 (1994).
The following is multiple choice question (with options) to answer.
If a rabbit hears a distant sound clearly, it can be attributed to its | [
"sensitive nose",
"soft fur",
"elongated ears",
"long feet"
] | C | long ears are used for releasing heat by a jackrabbit |
OpenBookQA | OpenBookQA-3127 | exoplanet, terrestrial-planets
I don't think that the authors are claiming that this is exactly what all the planets are made of, but simply illustrating that at present there do not seem to be any large deviations from such a composition (for example, planets that are made solely of iron).
There are relatively few planets on this diagram, because it is difficult to obtain the masses of small transiting planets (it requires detection of the doppler shift caused by the pull of the planet on its host star).
Of course different models yield somewhat different results. For instance, Wagner et al. (2012) used the same data for Kepler-10b and CoRoT-7b and their own detailed models to argue that these planets have an iron core that makes up about 60% of the planet - i.e. a lot more than makes up the Earth.
At the moment the data for the lowest mass planets currently indicate that there could only be a limited amount of diversity. But the information that we are working with, the sample size, and the fact that only masses and radii are
determined, is too sparse to be sure.
From a theoretical point of view there are many ideas. The basic concept about the formation of the terrestrial-type planets is that they form (relatively) close in to the parent star and have compositions that are reflective of what elements and minerals can condense out of the protoplanetary disk at high temperatures. This in turn depends on the balance of elements that are present in the protoplanetary disk, where in the disk the planet forms, the detailed structure of the protoplanetary disk, how it cools and how planets migrate in the disk. Unsurprisingly, by varying some of these conditions it is possible to create planets with a wide variety of compositions, which as I said above, appears to be mildly contradicted by the available evidence. At the most basic level we understand why the Earth and other terrestrial planets are comparatively lacking in "volatile" elements like hydrogen and helium (and to some extent C, N, O and noble gases), because they (or minerals containing them) could not condense at the high temperatures close to the proto-Sun.
The following is multiple choice question (with options) to answer.
which of these has the most similar component as the earth itself? | [
"the stone in the yard",
"a loaf of bread",
"a can of soup",
"a glass of water"
] | A | Earth is made of rock |
OpenBookQA | OpenBookQA-3128 | evolution, zoology, adaptation
One answer that came to mind is domestic animals - the horse and dog in prehistory, the cat in ancient Egypt, etc. That seems too obvious on one hand, and on the other hand may not really be an answer, as there seems to be no indication that pre-domestic animals were endangered by humans in any meaningful way. Are there animals that have significantly adapted themselves to surviving as wild animals in human-influenced environments? Note: This is an answer to the last line of your question.
A classical example of animals adapting to the influence of humans on their environment is the adaption of the Peppered Moth.
Here is a brief summary:
The peppered moth was originally a mostly unpigmented animal (<1800). During the industrial revolution in the southern parts of the UK a lot of coal was burned. This led to soot blackening the countryside. Soon afterwards, a fully pigmented variety was first observed. Only a hundred years later, in 1895, this pigmented variety almost completely displaced the unpigmented variety.
It has been shown that the pigmentation is under strong selective pressure as birds hunt these moths. Since birds rely on their visual system to detect their prey, the variety that blends in with its environment (=camouflage) has a selective advantage over the variety that stands out.
As pointed out by Tim in the comments, since the 1970s there has been a rapid reversal with unpigmented animals being more abundant. As far as I understand, it is accepted that this reversal is due to a decrease in human induced air pollution leading to less sooty barks on trees which makes the unpigmented variety harder to prey upon.
Addendum: genetic basis of adaption
In a beautiful recent study, the causal mutation for the pigmented, or melanic, variety was identified: A ~9kb transposon insertion in the first intron of the gene cortex. The authors calculate that this mutation happened in the year 1819, a few years after the industrial revolution was in full swing. The interpretation is that due to sooty tree bark this mutation, causing pigmented moth, was under strong selection.
The following is multiple choice question (with options) to answer.
if the local forest is cut down, which one of these animal's habitat might be affected? | [
"a student living in a townhouse",
"a man who lives in the city",
"a dog who lives in a pound",
"a rabbit who lives in a hole"
] | D | some rabbits live in forests |
OpenBookQA | OpenBookQA-3129 | electricity, electric-circuits, electric-current, electrical-resistance, voltage
Title: Why don't we get a shock touching neutral wire? Neutral wire has a V same as ground i.e almost 0. Also it carries some current. So if we touch the wire don't we to become a part of the circuit? Even if we are on the ground and current should flow through us, but I read we don't get a shock as there is no potential difference between ground and neutral wire, but the current was already flowing from live wire (220 V) to 0, so shouldn't we get a shock? Do not touch even the neutral wire in a live circuit! There are numerous failure modes that could make you dead wrong about not getting shocked.
The neutral wire does have current going through it. However, we do not get shocked when we touch something with current going through it, we get shocked when current goes through us. In this case all of the current that enters one end of the section of wire we are touching also leaves the other end. None goes through us so we don’t get shocked.
Why does no current go through us? From the perspective of a circuit we are, to a first approximation, just a big human shaped resistor. The current through a resistor is proportional to the voltage across it. Since the neutral is at the same voltage as the ground, both our head and our feet are at 0 V. So the voltage across us is 0 V and therefore the current is 0 A.
The following is multiple choice question (with options) to answer.
A shock running through a wire will | [
"send sand through the wire",
"send water through the wire",
"send smoke through a town",
"send reactions through the wire"
] | D | sending electricity through a conductor causes electric current to flow through that conductor |
OpenBookQA | OpenBookQA-3130 | genetics, entomology
Title: Why do ladybugs have a different number of points on their backs Everytime I see a ladybug I ask myself this question.
Why does every ladybug have a different amount of points on its back? Is it because of its age? Or because of its genes? Is it inheritable? The spots on the back of Ladybugs over the surface is defense mechanism to avoid predators. The spots come in different shapes and different numbers. Some say that those dots tell us their age. Since some ladybugs have 24 spots which means its age would be 24 years and that is not at all possible. So this is a popular misconception running around us.
But the real truth about the number of spots on the ladybugs' back is:
The number of spots on a ladybug does have significance. The spots and other markings do help you identify the species of ladybug. Some species have no spots at all. The record-holder for most spots is the 24-spot ladybug ( Subcoccinella 24-punctata), which has 24 spots, of course. Ladybugs aren't always red with black spots, either. The twice-stabbed ladybug ( Chilocorus stigma) is black with two red spots.
So now we know that the number of spots on the back of Ladybugs will help us to identify what species it belongs to. To give an insight into different species of them you can refer to this Identifying Ladybugs.
The above image shows different species of Ladybugs where you can see the varying number of spots in each bugs' back. More information can be found here Stripes on Ladybugs.
The following is multiple choice question (with options) to answer.
When a lady beetle is grown up, she may spend time | [
"laying a clutch",
"making a memory",
"making friends",
"seeing the sights"
] | A | a female insect lays eggs during the adult stage of an insect 's life cycle |
OpenBookQA | OpenBookQA-3131 | classical-mechanics
the other car hits you and starts compressing your car's crumple zone.
the collision force exceeds your braking force and your car starts accelerating. Your car's crumple zone is still being compressed.
the crumple zone is fully compressed so both cars are now moving at the same speed and your brakes are slowing both cars.
During phase 1 your car is stationary so you feel no force. If the collision is low speed the other car may come to rest before your car starts to skid, and you feel no force at all.
However all but the most trivial collisions are likely to apply more force than your brakes can resist, and you enter phase 2. To calculate the force you feel in phase 2 is quite involved as you'd have to know the force distance curve for compression of the crumple zone. I did Google to see if I could find this data, but without success. Anyhow, it should be obvious that the force during phase two will be less than you'd feel if the brakes weren't on.
Phase three is interesting because it's where you get the whiplash. Assuming your headrest is properly adjusted your head won't move much in phase two. However when you enter phase three your own brakes will jerk you forward. To reduce this (and as above assuming there are no 18 wheelers around) you should release the brakes.
So for low speed collisions you should leave the brakes off, but for high speed collisions hit the brakes during the collision and release them as soon as the two cars have stopped moving relative to each other.
Having said all this, the collision you describe happened to me a few years ago (I'm sure it's hapened to lots of us) and I hit the brakes and held them on. I'm happy to report I suffered no harm, though my car was a write-off. I would advise my children to always hit the brakes and leave them on. Risking whiplash is better than being pushed across the junction or into the back of the car in front of you.
The following is multiple choice question (with options) to answer.
Hitting the brakes hard leaves rubber on the road due to | [
"the sun",
"abrasion",
"plastic tires",
"metal roadways"
] | B | skidding causes friction |
OpenBookQA | OpenBookQA-3132 | the-moon, night-sky
And another useful reference at planetarium.madison.k12.wi.us:
At the beginning of Winter, when it's nighttime all of the time, the moon would be in the sky for the 2 weeks closest to Full Moon, and then below the horizon for the next 2 weeks. And at the beginning of Spring (click on the graphic), when the sun is at sunrise all of the time, the moon would be up in the sky for the 2 weeks closest to First Quarter (waxing), and then below the horizon for the next 2 weeks.
The animated graphic above shows what we would see from the North Pole if we went out every day at noon, for 14 days in a row, from March 1st to March 14, 2006. We start with a thin crescent moon near the horizon, and end with a full moon near the horizon. Halfway through, the First Quarter moon would be when the moon is highest above the horizon.
Keep in mind, that if you were observing the moon constantly, throughout a 24 hour period, the moon would seem to move to the right in the sky along with the sun, stars, and planets due to the Earth's rotation. Nothing would seem to rise and set: they would just seem to circle around you.
The following is multiple choice question (with options) to answer.
a complete lunar cycle takes about | [
"a month",
"a year",
"a week",
"a day"
] | A | a revolution of the moon around the Earth takes 1 month |
OpenBookQA | OpenBookQA-3133 | c++, game-of-life, opencv
void nextRound() {
std::vector <std::vector<bool>> ret(this->height, std::vector<bool>(width, false));
for (auto y = 0UL; y < this->cells.size(); y++) {
for (auto x = 0UL; x < this->cells[y].size(); x++) {
int aliveNs = this->aliveNeighbors(x, y);
if (!cells[y][x]) {
if (aliveNs == 3) {
ret[y][x] = true;
}
} else {
if (aliveNs < 2 || aliveNs > 3) {
ret[y][x] = false;
} else {
ret[y][x] = true;
}
}
}
}
this->cells = ret;
}
cv::Mat render() const {
cv::Mat ret = cv::Mat::zeros(width * UPSAMPLING, height * UPSAMPLING, CV_8UC3);
for (auto y = 0UL; y < this->cells.size(); y++) {
for (auto x = 0UL; x < this->cells[y].size(); x++) {
if (cells[y][x]) {
cv::Vec3b color(random(0, 255), random(0, 255), random(0, 255));
for (auto kx = 1; kx < UPSAMPLING; kx++) {
for (auto ky = 1; ky < UPSAMPLING; ky++) {
ret.at<cv::Vec3b>(x * UPSAMPLING + kx, y * UPSAMPLING + ky) = color;
}
}
}
}
}
return ret;
}
};
The following is multiple choice question (with options) to answer.
If crops are rotated then the crops planted would look like | [
"tomato, tomato, tomato, tomato",
"beans, corn, peas, cucumbers",
"beans, beans, beans, beans",
"corn, corn, corn, corn,"
] | B | crop rotation is when different crops are planted on a field in different years |
OpenBookQA | OpenBookQA-3134 | species-identification, theoretical-biology, taxonomy, literature, bioluminescence
Title: Looking for the closest example of life forms similar to some mathematical patterns
Caveat: this is my first question here, it is quite interdisciplinary, but I hope to be in the correct place to ask. I am a user of Mathematics Stack Exchange since some years ago, and this question is related with some questions there (here, here whose general formula is discussed here and here).
Context: I am preparing a mathematical paper regarding a new family of dynamical systems (if you are not familiar with the concept, simplifying the idea it is a mathematical formula in which starting from a initial value, once applied to the formula the resulting value is again applied to the formula, and so on, finally the values are plotted and eventually a -sometimes interesting- pattern emerges) whose attractors (plotted patterns) in the present case seem to have unexpected pareidolic properties.
Basically some of the patterns generated by these systems show similarities with some structures of invertebrate life forms, specially insects, marine jellyfish, and zooplancton and also due to the patterns of the accumulation of points, also with life forms presenting bioluminescence properties.
For each interesting pattern so far I have tried to find the closest life form example, to compare both the model and the life form patterns.
So my target is including in the paper the closest life form similar to each mathematical pattern. Initially it is just a pareidolic coincidence, but it might be interesting if the mathematical formula can resemble models of some organic structures.
These are the ones I have been able to gather, both the model and the closest life form I found. The pictures I am using at the right side of and below the images are just for the sake of completeness (they belong to their respective owners, I do not own them, if there is any problem I will remove them, so just please let me know). The formula can be verified at the MSE links I have added at the beginning of the question and the Python code to generate them is in this link (please feel free to use it and modify it). The questions are after the examples (click to enlarge):
Patterns similar to thorax and abdomen of Bembicini wasp, head and body of Turritopsis dohrnii (inmortal jellyfish) and Tardigrade limbs:
Patters similar to Drain fly:
The following is multiple choice question (with options) to answer.
Which is likeliest to metamorphose? | [
"a live insect",
"a human",
"a plant",
"a dead butterfly"
] | A | metamorphosis is a stage in the life cycle process of some animals |
OpenBookQA | OpenBookQA-3135 | Note: Before you can calculate how many plants will be required to fill a given area you'll need to first determine the total square feet of the planting bed. Many online calculators use this formula: $$Total\,number\,of\,plants = {Area\,of\,garden \over Plant\,spacing^2}$$. Image Credit: Getty Images Calculating even spacing is an essential carpentry technique that you might need for things like fence pickets, railing balusters, or decking planks. How much food you need to eat everyday based off your weight, height, age, and activity. Hedges with plants 60cm apart "fill in" quicker than those planted 100cm apart but you get just as good a ⦠Get a Quote for. Planting fruit trees too close together causes them to shade each other and produce lower yields and lower quality fruit. Now simply choose one of these options and start planting! Area in Square Feet: Plant Spacing in Inches: Number of Trees in Bed: Calculate *Only enter one bed at a time, do not combine bed square footages and enter as one. Length Member Width ... Decimal Inch or Metric mm. Fill in any two fields and this tool will calculate the third field. The plant quantity calculator works out the area of the garden based on the measurements you provide (in metric or imperial units) using the formula: $$Area\,of\,garden = Length \times Width$$ Our calculator allows you to use both square and triangular patterns for the plants with equal coverage. This calculator figures seed spacing and population. Spacings Calculator Metric Never use a chart again! Our calculator allows you to use both square and triangular patterns for the plants with equal coverage. A Tree Spacing Calculator that will calculate the number of trees per acre and spacing between trees and tree rows. ... Calc # of plants needed in a rectangular and triangular grid from area and spacing between plants. If you desire to only plant the perimeter, click the checkbox "Perimeter only". Toro dripline calculator. feet) x (Spacing Multiplier) = Number of plants needed (Area is 2 feet by 25 feet = 50 sq. There are two distance requirements for the calculation; the distance between tree rows and the distance between the trees themselves. Next, to calculate the
The following is multiple choice question (with options) to answer.
A bean sprout will beautifully boom if given plenty of access to | [
"salted dirt",
"H2O",
"sticky napkins",
"searing heat"
] | B | a plants require water for to grow |
OpenBookQA | OpenBookQA-3136 | spectroscopy
Title: Why does the tungsten filament in a lightbulb produce a full(ish) spectrum instead of tungsten's emission spectrum? I only roughly understand how a spectroscope works, so that may be part of the problem. I don't understand what is different about what causes the materials to emit light. The light emitted by a tungsten filament light bulb is due to heating the tungsten filament to a very high temperature. Tungsten has a high melting temperature so the filament can get very hot. The light is like heating a piece of metal till it glows, and then keep heating it until it is 'white' hot. The light is not due to atomic transitions.
The melting point of Tungsten is around 3410°C (6170°F) and the temperature reached in a light bulb is around 3,000°C
The following is multiple choice question (with options) to answer.
A filament that is in a glass container will be this when a switch is flipped to cause glass to glow: | [
"dark",
"toasty",
"cold",
"icy"
] | B | an incandescent light bulb converts electricity into heat by sending electricity through a filament |
OpenBookQA | OpenBookQA-3137 | food
Title: Why might food go bad in an oxygen-free environment? I was recently watching a video from the International Space Station (Making a peanut butter sandwich in space), and I noticed he mentioned that a tortilla kept in an oxygen-free environment could last up to 18 months. Impressive, but it got me thinking: Why would some foods ever spoil if kept in a state where molds would not be able to grow? Would it be that other micro-organisms in things like the moisture present in the food eventually take their natural toll? Just a curious thought I had while watching through these awesome ISS videos.
Thanks for any answers! First of all, you assumed that this tortilla went bad after 18 month, not that austranaughts just decided to eat it?
More importantly, there is thing called anaerobs. Just like your muscle don't use oxygen in times of acute stress (force requirement), so there are organisms that don't care much about oxygen. As it happens in muscle, it happens in yeast during fermentation when sugars are turned into alcohols and released energy is used to propel molecular machinery. So, if there are sugar molecules on tortilla, there are still microbes that willing to prosper on it.
The following is multiple choice question (with options) to answer.
A bear in the arctic can go a long time without eating | [
"if it is focused",
"if it is determined",
"if it is working",
"if it has excess chub"
] | D | an animal can survive in an environment with little food by storing fat |
OpenBookQA | OpenBookQA-3138 | electromagnetism, electricity, experimental-physics, magnetic-fields
Title: A confusion with solenoidal windings I have seen in solenoids, toroids, transformers, electromagnets and machines that the core is pretty insulated. Over this the winding coil is wrapped but it is a bare coil (turns are not insulated to each other). So, how does it work? Won`t there be a short circuited path (current will find a shorter path and flow through it and will not flow through the whole winding)? I have more precisely and vividly stated it in the picture() Most wires like this are, in fact, insulated; a very thin layer of enamel coats the wires. You can gently scrape away this layer with a key or some sandpaper; the copper beneath will be a slightly different colour.
The following is multiple choice question (with options) to answer.
If a thing is electrically insulated, then it is | [
"wood inside, metal inside",
"a random mixture of materials",
"metal inside, metal outside",
"metal inside, other material outside"
] | D | electrical insulation requires wrapping a conductor in an insulator |
OpenBookQA | OpenBookQA-3139 | homework-and-exercises, pressure
Title: Necessary air pressure in flexible vessel to lift a certain mass I have the following situation in mind:
A big airtight bag of arbitrary shape with a person standing on it. The bag gets inflated with air to lift the person.
Assuming that the bag is much larger than the persons footprint, how do I find the minimal overpressure in the bag that I need to lift the person of the ground?
I was thinking of just dividing the normal force of the standing person by the footprint area, but I am not sure on that approach
$$F_n = 80×9.81 = 784\text{ N}$$ $$P_n = \frac{784}{0.2×0.3} = 13066\text{ Pa}$$
I have the feeling that the bag dimensions play a role as well, as intuitively I would say that to do this, a small bag would work better than a big bag, but again I'm not sure... It is just as simple as you suggest. At the moment my feet are exerting a pressure on the ground of my weight divided by whatever the area of my shoes is and the pressure exerted by the ground on me is what keeps me stationary. Exactly the same applies to your air bag. once the air pressure is the same as the pressure you exert on the bag it will support you.
But there are a couple of extra things to consider. When you stand on the bag you will compress the air in it and you'll sink until the air is compressed enough to match the pressure of your shoes. So the initial pressure can be lower than your shoe pressure and the bag can still keep you off the ground.
You mention the bag size, it's probably easier to compress the gas a lot in a small bag than in a large bag, so a small bag would probably work better. There's nothing especially fundamental about this; it's just that a large bag allows more room for the air to move into as your feet compress it.
The following is multiple choice question (with options) to answer.
Rising air pressure means that I should bring | [
"black holes",
"sunblock",
"time travel",
"magic"
] | B | as altitude increases , air pressure will decrease |
OpenBookQA | OpenBookQA-3140 | humidity, air-pollution
Title: Does usual city pollution have effects on relative humidity? I've noticed that in a rural area with low pollution the relative humidity is constantly lower than the humidity in a high polluted city. Is there any correlation between pollution and humidity? By way of reference, "humidity depends on water vaporization and condensation, which, in turn, mainly depends on temperature".
From the information you have supplied in your comments. There are waters in Bucharest and forests in the suburbs, but no waters or forests where the country house is located.
From your information, Bucharest has a number of sources of atmospheric water vapour, the river that flows through it (evaporation of water) and the forests in the suburbs (transpiration of water). Additionally, motor vehicle exhausts will increase the humidity as water vapour is one of the products of the combustion of hydrocarbons.
The warmer the air, the greater its capacity to hold moisture. Cities tend to be warmer than rural areas due to the heat island effect, which is the result of modifying land surfaces and the generation of waste heat.
Humidity in the rural location will arise from evaporation of water in the soil and transpiration from crops or grasses. Such transpiration will produce less water vapour than forests. Additionally, the rural location will have significantly fewer cars producing water vapour in their exhausts. Consequently, the rural location will be less humid than the city.
The reason why Bucharest is more humid that the rural location has more to do with the greater availability and vaporization of water in Bucharest and the temperature of Bucharest than the amount of pollution in Bucharest.
The following is multiple choice question (with options) to answer.
A source of pollution might be | [
"recycling glass and plastic",
"creating a new use for old glass",
"throwing plastic in the pacific",
"finding a new use for old clothes"
] | C | fertilizers are a source of pollution |
OpenBookQA | OpenBookQA-3141 | structures
Title: Siding for Industrial Shed: Rain protection vs Ventilation When building a 12 m tall industrial shed with a peaked roof it is desirable that the sides of the shed should stay open as much as possible for ventilation / safety / access concerns.
On the other hand, an entirely open side from top to bottom might cause a lot of rain exposure when the rain comes in angled?
Is there a trade-off possible? Perhaps to enclose sides till a certain distance below the roof edge? Any heuristics about how much? (I've shown 4000 mm in the sketch below)
The contents inside the shed are relatively robust / waterproof & hence absolute rain protection is not needed. This will very much depend on the exposure of the building to wind as this is what will drive the rain in at an angle. So you really need to consider the prevailing wind direction and how sheltered the building is by other nearby structures etc.
If may be that if the prevailing wind direction is fairly consistent you can have one side more open than another.
Another option is to have panels which can be folded down when required eg if you have 4000mm of fixed cladding, you could have the same in fold-down form (this arrangement is fairly common in barns).
Also it depends what access you need obviously forklifts will need more height clearance than pedestrians.
You could also consider using strip curtains for at least part of the height.
The following is multiple choice question (with options) to answer.
Rain can damage | [
"happiness",
"the carpet",
"love",
"Space"
] | B | An example of stormy weather is rain |
OpenBookQA | OpenBookQA-3142 | thermodynamics, energy, power
Toyota Corolla, 13 gallon tank, 20% efficiency, 103 kWh usable energy
Tesla Roadster, 56 kWh battery capacity
Chevy Volt, 16 kWh battery capacity
If we compare a liquid Nitrogen car to the Chevy Volt it might not be so bad. But why would we do that? That car can still augment its range with gasoline. A part of the argument for electric cars is that you don't have the same energy loss from idling. Would that be true for a liquid Nitrogen car? There is no reason to believe that.
Let's say we assume a reasonable efficiency of half the isothermal process, which is illustrated in Figure 2 of the reference. Let's also say we'll hold 50 kWh of usable energy in the tank (even though this could still cause range problems). We've increased the tank size by a factor of 4 and the weight of the full tank is now around $1000 kg$. This is close to what many cars weigh.
The energy content relative to gasoline, as well as the alternatives, kills the idea. It would seem to require extremely optimistic assumptions to make it a reasonable proposal before we even get into the discussion about infrastructure needed to make it happen. The most fair comparison would be to other cars that also use alternative fuels, but it fails there too. EVs seem to have better viability on the basis of simple energetics. Maybe you're concerned that we'll run out of Lithium. A vehicle powered by compressed natural gas (not even the super-high pressure tanks that many have hope in) would blow it away, and the tank would be more manageable. Plus the fuel would be (dramatically) cheaper. Plus the infrastructure would be there. Plus, the engine is a proven design. We could do better with coal-to-liquids, we could probably do better with biofuels.
The following is multiple choice question (with options) to answer.
Battery powered vehicles have less emissions than | [
"lawnmowers",
"wind turbines",
"solar power",
"dragsters"
] | D | electricity causes less pollution than gasoline |
OpenBookQA | OpenBookQA-3143 | evolution, molecular-biology, molecular-evolution, abiogenesis
The issue isn't actually as clear-cut as it may seem, since there is a very wide unknown space between what we consider the most archaic forms of life, and any entity that could plausibly arise via purely abiotic processes; every theory of abiogenesis does assume that a lot of the features we consider essential to life must have arisen after some kind of replication appeared, meaning those features would have evolved. So there definitely is some evolutionary biology involved in investigating abiogenesis, and maybe if we ever solve abiogenesis it will be folded into the ToE (like I said, the ToE is actually a complex set of theories and observations, not one single thing. So while our understanding of what the theory says and can say currently excludes abiogenesis, our understanding and definition of the theory could evolve). But we haven't, and it currently isn't.
You need to edit your question however, because it is completely unclear from the title or text that you are asking about abiogenesis. Your question sounds like it's about embryonic development or biochemistry. Those are the current instances we have of organisms forming; whatever processes were at work in creating the very first life, well for one thing maybe we wouldn't want to call whatever that was an "organism", but more to the point those processes cannot happen today. The atmosphere is wrong and too full of oxygen, there are organisms everywhere vaccuuming up whatever resources those original biochemical processes might have used, basically there is likely no chemical environment on modern Earth that's anything like the chemical environment life originated in.
To answer your question though, abiogenesis is currently an unsolved question, so no, Science does not have an explanation of how the first organisms formed. But if you want to have an idea of how things could have happened, what the challenges are in figuring things out, and what things Science currently considers likely or impossible, there is a lot of active research in the field and many different hypotheses. The Wikipedia page for Abiogenesis has a fairly comprehensive rundown on this.
This video describes one of them (my favorite and the first I've found actually convincing, I have no expertise whatsoever to base this on but I plug it anyway; if nothing else it gives an appreciation for what kind of things the researchers in this field look at when thinking abiogenesis) :
The following is multiple choice question (with options) to answer.
If an organism is existing then it is made up of | [
"cola",
"life material",
"soil",
"sap"
] | B | an organism is a source of organic matter |
OpenBookQA | OpenBookQA-3144 | climate-change, climatology
Thus, your question is a little misconstrued: we can't answer "Who are the 3%?" because the 3% are research articles rather than people. However, we can ask "Which are the 3% of published research abstracts which do not support the scientific consensus?" And since Cook et al. (2013) is an open access paper with supporting data provided, you can easily answer this question for yourself: simply download the data file from the supplementary data page and look at the papers with an endorsement rating of 5, 6, or 7. (It's in CSV format, so is easy to load into a spreadsheet or text editor.) Further supplementary data is available from the project page at Skeptical Science, and replication of the research is actively encouraged. If you're interested in the actual people behind the 3% of "non-consensus" papers you can look at the author lists for those publications (though of course there's no guarantee that all those authors would still stand by all their conclusions).
I suggest that you start your investigations by reading the paper itself. It's clear and concise, and will give you much more thorough information about the methodology and supporting data than I've been able to fit into this answer.
The following is multiple choice question (with options) to answer.
Which would an ecologically minded individual most support? | [
"oil",
"gas",
"fracking",
"windmills"
] | D | wind is a renewable resource |
OpenBookQA | OpenBookQA-3145 | # 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 is the most likely scenario | [
"squirrels save nuts when summer is hotter than the current season",
"squirrels never save food",
"squirrels eat when it rains outside only",
"squirrels save nuts when humans make them"
] | A | when available resources decrease in an environment , organisms have to conserve those resources |
OpenBookQA | OpenBookQA-3146 | quantum-spin, atoms
The bonds between the atoms are obviously split when the paper is torn, but is there a way to put them back together?
the answer is yes, because this is precisely why paper recycling works. The incoming used paper is washed, to remove ink and other contaminants, and then left to soak in a particular solution (the composition of which partly determines the color, consistency, strength, etc. of the resulting paper), where it eventually turns into a slurry. Paper is made of long fibers of cellulose arranged essentially randomly; when immersed in water, those fibers spread out throughout the solution. Then the slurry is rolled into sheets and left to dry; as the water leaves, the cellulose fibers end up weakly attracted to each other (the "weak" part is important; it's why you can easily tear a piece of paper in the first place), which leads to a similar kind of random arrangement of weakly-bonded cellulose fibers that we start with.
The following is multiple choice question (with options) to answer.
Recycling products such as papers can help the environment to | [
"demolish",
"heal",
"fall apart",
"be destroyed"
] | B | recycling has a positive impact on the environment |
OpenBookQA | OpenBookQA-3147 | radiation
You see similar things happening here. The metal rod at the top of the lamp acts as a capacitive ground - given the very high voltage, a tiny charge will flow from the tip of the filament to the rod. There is a small amount of gas in the tube which is ionized and gives rise to the light you see. The electrons eventually bombard the metal "anode" and produce Bremsstrahlung - note that without the metal, you were getting a glow and no reading on the Geiger counter. There is a similar demonstration online which is more convincing in its use of conventional materials, but which otherwise shows many of the same phenomena.
It is almost certainly very inefficient. Most of the energy in an X-ray tube is converted to heat as the electrons burrow too deeply into the tungsten target for their radiation to escape- apart from the fact that only the most violent deceleration produces X-rays with high enough energy to penetrate the bulb and be detected.
I noticed that when the "alpha window" was removed, the reading in your video went up. Since there was also a biscuit tin and glass bulb in the way I suspect there was a lot more low energy radiation generated than was detected. Good stuff for skin cancer.
The experiment as shown should not be repeated. Not only were the HV precautions extremely poor, but so were the radiation safety precautions. Please don't try this at home...
The following is multiple choice question (with options) to answer.
If a flashlight is having difficulty working a person should check | [
"the bottom hook",
"the energy hole",
"the glass window",
"the solar flares"
] | B | a flashlight requires a source of electricity to produce light |
OpenBookQA | OpenBookQA-3148 | human-biology, reproduction
Title: Why are animal births not taken as seriously as human births? When humans give birth, more than often medical assistance is needed. Others gather around and frantically look for any way to help. But when an animal gives birth, it is usually seen as a moment where you give the female its space and let the birth occur naturally and without any assistance. The animal is of course in serious pain just as a female human but this is more than often not taken into account. Why is it that animal births are not taken as seriously? Our heads are bigger.
There's some debate on the issue, but in essence, human brains, and therefore heads, are very large relative to our body size. This is handy for all the intelligent things we like to do, but can be rather painful during birth. Because we walk upright, the size of a newborn's head is actually a non-trivial fact during the birthing process. There are two major implications.
The first is that human birth hurts. You can watch the birth of other animals and they seem to brush it off, but for humans, forcing that huge head through a relatively small birth canal is difficult. Evolution has (supposedly) limited the size of the hips because, while that would allow an easier birthing process, it would negatively impact our ability to walk. As such, it has to hurt.
Secondly, in order to make the process easier, humans rotate during birth. The end result is that, unlike even other closely related primates, humans come out backward in a way that is very difficult for a birthing female to attend to. This almost requires having another person or two on hand to help out. This would, of course, be a huge reinforcement for social connections.
A few books I know of touch on this. Up From Dragons deals with the brain size/hip size issue and The Invisible Sex talks about rotation during the birthing process and the social implications.
The following is multiple choice question (with options) to answer.
If a kitten is unable to nurse from birth | [
"it will expire",
"sleep",
"decide to leave",
"it will laugh"
] | A | a mammal usually nurses its offspring |
OpenBookQA | OpenBookQA-3149 | • $P_2$ will fly $\big[1-(d+r+y)\big]$ distance away from the airport in the counter-clockwise direction to meet up with $P_3$.
• At this point, $P_2$ will donate $z$ fuel to $P_3$.
• $P_2$ and $P_3$ will then both fly back $z$ distance, arriving at a distance of $1-d-r-y-z$ from the airport with no fuel.
• After refuelling at the airport, $P_1$ will fly the distance towards $P_2$ and $P_3$ and refund each of them for that much fuel. All three planes will then head back to the airport together.
From this, we must have
• $0 \leqslant s\leqslant d/3$: $P_1$ can fly $s$ distance forward and backwards, and refund $P_2$ for $s$ distance
• $z\geqslant 0$: cannot donate negative fuel
• $2x + 1-d-r-y \leqslant d+r+y$: $P_3$ must not run out of fuel before $P_2$ can reach it again
• $1-d-r-y - z \leqslant d/4$: $P_1$ can reach $P_2$ and $P_3$, refund them both, and the three of them will have enough fuel to head back to the airport
• $2x + 2s + 1-d-r-y - z\leqslant d+r+y + z$: $P_2$ and $P_3$ must not run out of fuel before $P_1$ can reach them again
Putting these together:
The following is multiple choice question (with options) to answer.
A plane taking off from an airport will seem what as it flies away | [
"empty",
"smaller",
"the same",
"bigger"
] | B | as distance to an object increases , that object will appear smaller |
OpenBookQA | OpenBookQA-3150 | 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 person is lacking a skeletal system they are | [
"thrilled",
"muscular",
"kind",
"spineless"
] | D | skeletal system is made of bones |
OpenBookQA | OpenBookQA-3151 | evolution, zoology, taxonomy, phylogenetics
The apomorphy that defines the tetrapods is "paired limbs". You have Amphibia to the left and Amniota to the right, whose apomorphy is " egg with extraembrionic membranes". Inside them, you have Reptilia, whose apomorphies are "skull with upper and lower fenestra and beta-keratin in epidermis". Turtles came from an ancestor with these characteristics. So, turtles belong to the monophyletic group of "Reptiles".
Post scriptum: You wrote that "turtles (specifically sea turtles) live on both land and water, very much like amphibians". Just a curiosity: the reason why sea turtles leave the water (sea) from time to time shows exactly that they are not amphibians! Amphibians, being non-amniotes, have eggs that survive under water (actually, with few exceptions, they need to be under water). Turtles, on the other hand, are amniotes, and the amniotic egg cannot be laid under water. That's why the turtles have to leave the water to lay eggs: because, contrary to the amphibians, they cannot lay eggs under water.
The following is multiple choice question (with options) to answer.
A carp and a platypus share all attributes aside from | [
"blood heating ability",
"egg laying",
"having mouths",
"having tails"
] | A | a mammal is warm-blooded |
OpenBookQA | OpenBookQA-3152 | space, vacuum
Title: Effects on a tree exposed to the vacuum of Space My wife's kindergarten class asked, "What would happen to a tree planted on the moon?" Aside from the obvious that it would die from lack of water/air, what physical effects would happen to a tree exposed to the vacuum of Space? This is a question for a biologist.
To start with, I guess it would freeze dry, by the water evaporating due to the lack of atmosphere, as Ted observed. If you have forgotten an unwrapped piece of food in the freezer you would know what it means.
Then also the rest of the molecules which are made up mostly of Carbon and Hydrogen would slowly sublimate. If in the sun, much faster.
Now if one assumes a bubble of atmosphere and appropriate water and fertilizer, and the question concerns if the moon soil could support a plant, the answer is , yes, if earth soil microorganisms are introduced into the moon soil where the plant is planted. The technique exists used for improving poor soils.
(I recently learned about it from discussions about planting a sour cherry tree in poor soil.)
The following is multiple choice question (with options) to answer.
if a tree fell down and dried with a hole in it, which of these would likely be in it? | [
"A two hundred pound lion",
"a great white shark",
"a striped tail nut eater",
"a wild female antelope"
] | C | some raccoons live in hollow logs |
OpenBookQA | OpenBookQA-3153 | electricity, home-experiment
When the streamer edge arrives at oil surface, negatively charged particles (electrons and negative O2 ions) are deposited on the surface, creating a local negatively charged spot. At this particular spot the pressure of oil increases, which from Navier-Stokes equations cause the fluid to move in the direction of decreasing pressure.
This particular phenomenon has been studied experimentally in the late 90s. The motion of oil is called Electrohydrodynamic surface waves (EHD). Have a look at this paper where they study a very similar configuration to yours.
The following is multiple choice question (with options) to answer.
The running and moving liquid fluid during a storm causes what | [
"insects",
"weather damage",
"abrasion",
"lava"
] | B | erosion of soil has a negative impact on the environment |
OpenBookQA | OpenBookQA-3154 | # Express exactly two logically
Let C(x, y) : "x and y have chatted over the Internet"
where the domain for the variables x and y consists of all students in your class.
a ) There are two students in your class who have not chatted with each other over the Internet.
My answer: $\exists x \exists y[(x \not =y) \land \lnot C(x, y)]$
I googled it and mine found correct.
b ) There are exactly two students in your class who have not chatted with each other over the Internet.
My answer: $\exists x \exists y[(x \not =y) \land \lnot C(x, y) \land \forall a \forall b(\lnot C(a, b) \iff ((a = x \land b = y)\lor(a = y \land b = x)))]$
Am I correct for question b?
• I do think you are correct. I do not think it is the nicest way to put it. – Hugo Berndsen Nov 17 '16 at 16:37
I was going to comment on the ambiguity from the lack of braces but now that you've edited, I believe it is correct. I would remove the equivalence and just leave it as an implication as it is redundant and makes it a bit harder to read.
$\exists x \exists y[(x \not =y) \land \lnot C(x, y) \land \forall a \forall b(\lnot C(a, b) \implies ((a = x \land b = y)\lor(a = y \land b = x)))]$
EDIT: thinking further I feel like I want to add this as maybe somebody is (not) chatting with himself over the internet, but we don't want this to bother us.
$\exists x \exists y[(x \not =y) \land \lnot C(x, y) \land \forall a \forall b\{ [a\neq b \land \lnot C(a, b)] \implies ((a = x \land b = y)\lor(a = y \land b = x))\}]$
The following is multiple choice question (with options) to answer.
Which of the following is correct? | [
"The earth's strong gravitational pull causes a waxing gibbous to form",
"astrology causes a waxing gibbous to form",
"star maps cause a waxing gibbous to form",
"government satellites cause a waxing gibbous to form"
] | A | the moon orbiting the Earth causes the phases of the moon |
OpenBookQA | OpenBookQA-3155 | the-moon, moon-phases
A 95-percent illuminated moon appears half as bright as a full moon
Believe it or not, the moon is half as bright as a full moon about 2.4
days before and after a full moon. Even though about 95 percent of
the moon is illuminated at this time, and to most casual observers it
might still look like a "full" moon, its brightness is roughly 0.7
magnitudes less than at full phase, making it appear one-half as
bright.
Perhaps the extra few degrees of fullness really does make a noticeable difference. I'd assumed it wouldn't make a big difference but this article suggests it does.
The following is multiple choice question (with options) to answer.
If you miss seeing a full moon, how long will you have to wait until you get another chance? | [
"7 days",
"a month",
"a week",
"168 hours"
] | B | each of the moon 's phases usually occurs once per month |
OpenBookQA | OpenBookQA-3156 | 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.
the contents of which of these will attract a natural honey producer to it? | [
"a tree bark",
"a tree trunk",
"a colorful hibiscus",
"a green leaf"
] | C | nectar is used for attracting pollinators by plants |
OpenBookQA | OpenBookQA-3157 | newtonian-mechanics, conservation-laws
So generally the plate will move : it could translate and also rotate. Constraining forces (and torques) would be needed to keep it in place. If it is released it will move.
The following is multiple choice question (with options) to answer.
which of these need to be present for a tectonic plate movement | [
"a pool of molten lava",
"an ocean with fish",
"a river flowing north",
"a crack in the core"
] | D | a tectonic plate moves along a fault line |
OpenBookQA | OpenBookQA-3158 | newtonian-mechanics, forces, classical-mechanics, free-body-diagram
Title: If an object would be too tough to puncture while static, is it possible to pierce it while holding still and having it move toward you? In The Lord of the Rings it is claimed that no man has the strength to pierce the skin of the giant spider Shelob. In a dramatic turn of events, Shelob lunges at Sam with such force that she pierces herself with Sam's sword.
This seems physically impossible to me, assuming the real-world laws of physics are in effect. Wouldn't Sam need the strength to hold the sword in place in order to actually pierce, and by Newton's third law and the above claim, require impossible strength? Maybe this has something to do with impulse, which I never fully understood. There are three ways ways this might work, all of which using Shelob's own strength.
First, as noted in other answers, the sword could have been driven down until the hilt struck the floor and was braced that way.
The sword could have been held straight up with the arms and legs locked and the crosspiece of the sword pressed against the hands. In this stance, a body could withstand more force than the muscles could actively exert, and thus act as sufficient brace against Shelob's own superior strength.
The text seems to support that Shelob's body was hard. Piercing thus is a matter not of force, per se, but of impulse: mv = Ft. The harder the shell, likely the more a quick impulse will break it. Shelob could have moved with such speed against a thrust that the impulse time was shortened, and the strength of Sam's own thrust multiplied because of the shortened interval, since that equation rearranges to F = mv/t.
The following is multiple choice question (with options) to answer.
Hitting a spider web with your hand makes it impossible for a spider to | [
"play music",
"eat",
"fly",
"watch TV"
] | B | a spider web is used to capture food by spiders |
OpenBookQA | OpenBookQA-3159 | solar-eclipse
Title: Can you test solar eclipse glasses with a remote control? By putting solar eclipse glasses directly between a remote control IR emitter and device receiver, could some unsafe glasses be detected? My guess is most fake glasses are just blocking visible light at best, while safe ones should block the IR signal as well. It would not guarantee they are 100% safe, but it might be able to detect bad ones.
I know to check for the ISO logo, cert number, and buy from a reputable vendor recommenced by the American Astronomical Society (which I have). It would still be nice to double check pairs of glasses before giving them out to friends and family. Short answer: No.
Long answer: No. You're testing at a single wavelength. The Sun emits continuously at a variety of wavelengths from deep infrared to far ultraviolet. Testing with a single kind of radiation doesn't tell you much about the filter behavior at the other wavelengths.
Buy from the online vendors that specialize in selling astronomy equipment - the ones that all astronomers buy their gear from. They tend to know the stuff they're selling. The list of vendors on the AAS page is good.
The following is multiple choice question (with options) to answer.
To look at an eclipse you might be able to use | [
"nothing",
"telescope",
"Plain old sunglasses",
"a box"
] | D | looking directly at an eclipse of the Sun causes harm to the eyes |
OpenBookQA | OpenBookQA-3160 | soft-question, education
Title: Educational physics stories with a funny punchline As a physicist, when I'm giving lectures or during colloquiums, I usually find it necessary to have some appropriate and related jokes in hand. All of the best teachers have some, and they use them when they have to; so I think that it is a necessity of good teaching. On the math side we have this gem(although being closed and reopened several times); however on the physics side I couldn't find much. Hopefully this topic will help me and many others with this regard. David Morin has written some answers to the old question of Why Did the Chicken Cross the Road?, here at Harvard department of physics website.
To avoid an one-line answer, I bring some of them here that I found more interesting :
So...
Why Did the Chicken Cross the Road?
Albert Michelson and Edward Morley: Our experiment was a failure. We could not detect the road.
Werner Heisenberg: Because I made darn sure it was standing right next to me on this side
Albert Einstein: The chicken did not cross the road. The road passed beneath the chicken.
Ludwig Boltzmann: If you have enough chickens, it is a near certainty that one of them will cross the road.
John David Jackson: You’ll find out after you complete this 37-page calculation.
Henri Poincare: Let’s try changing the initial position of the chicken just a tiny, tiny, tiny bit, and….look, it’s now across the road!
Enrico Fermi: In estimating to the nearest power of 10 the number of chickens that cross the road, note that since fractional chickens are not allowed, the desired power must be at least zero. Therefore, at least one chicken crosses the road.
Richard Feynman: There was this good-looking rooster on the other side of the road, and he figured he’d skip all the games and just get to the point. So he asked the chicken if she’d like to come over to his side, and she said sure.
Erwin Schrodinger: The chicken doesn't cross the road. Rather, it exists simultaneously on both sides…..just don’t peek.
John Bell: Since there are no local hidden chickens, any hidden chickens you find must have come from far away. They therefore surely must have crossed at least one road on their way here.
The following is multiple choice question (with options) to answer.
Why did the chicken cross the road? | [
"to side with the foxes",
"to be made into chicken of the sea tuna fish",
"their habitat was flooded",
"because they crossed an evil sorcerer"
] | C | if a habitat can no longer support animals then those animals will move to another area |
OpenBookQA | OpenBookQA-3161 | everyday-chemistry, acid-base
Edit:
I would like to add a few details.
Assume that the acid is not concentrated but of suitable molarity to just cut the paper. I mean, to pierce through it and burning its edges to just make a nice cut. Like a glowing incense stick makes when made to touch a paper.
Also, the nip of the pen and the ink chamber are strongly inert; enough to survive the concentrated acid's attack and prevent leaking. Like, the chamber can be made of glass (in which acids are usually kept) and the nip can be made of galvanized/electroplated iron.
Or if there is still more, we can just make this into a thought experiment. You can pour anything into your pen. Is it a good idea? Most likely not. Is it dangerous? You bet! Is it a good idea to play with? NO! Whether it is legal or not to create such an object, you'll have to check with legislation in your country.
If you want paper to ignite on touch with this pen, you would need some truly strong acid (and probably undiluted). I'm certain that if this substance has the capability to burn paper, it would also corrode away the feed and nib of the pen. In the worst case, it will even eat through the ink container and leaking everywhere. In any way, this is no viable option to cut paper in a controlled fashion.
Is there a safer method? Well, there would be laser-assisted cutting of paper, but the good ol' knife or saw would still be cheaper.
The following is multiple choice question (with options) to answer.
if a person used a knife to repeatedly scrape an object, what will happen? | [
"the object will decrease in size",
"the object will become liquid",
"the object will increase in size",
"the object will change color"
] | A | scraping an object may cause small particles to break off of that object |
OpenBookQA | OpenBookQA-3162 | climate-change, climate
In this case, as it is an area that it is almost constantly cloudy with high humidity, temperature is varying just a little bit, and except the first day of the period, it seems that there is no relationship. In fact, on the second day there was a storm (I am living now at Singapore) and it is reflected in a quick change in temperature (both) and solar radiation.
Conclusion: It is not as simple as it seems.
Hope it helps!
The following is multiple choice question (with options) to answer.
Which is likely to cause changing weather in a specific location? | [
"delogging",
"human campers",
"rabbit mating",
"pet hamsters"
] | A | climate is the usual kind of weather in a location |
OpenBookQA | OpenBookQA-3163 | geophysics, data-formats, informatics
Title: What are the fields in Petrel's IESX seismic horizon file? I have a text file containing 23 seismic horizons from Petrel, Schlumberger's seismic earth interpretation and modelling tool, using the 2D IESX format. Here are the first few rows:
PROFILE Fault to seafloor TYPE 1 5 By Petrel 2014.2 (64-bit) 2d_ci7m_gf.ifdf m ms
SNAPPING PARAMETERS 5 2 2
4.19846879E+05 4.66812161E+06 1 14 2742.85 5460.00 16382.00 4262 2 276-109::normTOv
4.19840089E+05 4.66813210E+06 1 14 2756.25 5461.00 16383.00 4263 2 276-109::normTOv
4.19833299E+05 4.66814259E+06 1 14 2769.65 5461.00 16384.00 4264 2 276-109::normTOv
4.19826509E+05 4.66815308E+06 1 14 2783.05 5461.00 16385.00 4265 2 276-109::normTOv
4.19819720E+05 4.66816357E+06 1 14 2733.93 5462.00 16386.00 4266 2 276-109::normTOv
4.19812930E+05 4.66817406E+06 1 14 2809.85 5462.00 16387.00 4267 2 276-109::normTOv
...
Each horizon starts with two similar header rows. I'm not too worried about those (but it would be nice to know about them too). I'm more interested in the (400,000 or so) data rows. Here's what I surmise so far:
(float) — x location
(float) — y location
[1-9] (int) — seems to change with each interpreted segment of horizon
14 — no idea
(float) — two-way time
(float) — no idea
(float) — no idea
(int) — CDP or trace number
2 — no idea
(str) — line::dataset
The following is multiple choice question (with options) to answer.
Oil platforms originating from a number of oceanic placements can be related to an unintentional release of what? | [
"oil pumps",
"nuclear fission",
"biological created fuel",
"solar energy"
] | C | offshore oil platforms might cause oil to leak into the water |
OpenBookQA | OpenBookQA-3164 | zoology, sensation
Title: Can animals that rely heavily on sonar sense colour? Apparently there're species around as rely heavily on sonar to sense the world around them.
E.g. Bat, Dolphin, Whale ...
The humans, and other terrestrial beings in a lighted world are capable of distinguishing colour in varying degrees of acuity. Is this ability to sense colour in our environment applicable to species (terrestrial, avian, and marine) that rely heavily on sonar? Any animal using sound cannot sense color though sonar directly, though these animals are not entirely blind and can probably see colors in the infrared we can't.
Even on the darkest night there is some light around and all bats use this. Old World fruit bats have colour vision, which is useful to them as they are often quite active in daytime, roosting on trees in exposed positions, rather than tucked away in dark crevices like most microbats, which can see only in black-and-white.
Dolphins have additional senses in addition to seeing they can sense electrical fields. So if an animal has its eyes covered, they will seem to be able to do things you would not expect. Its not the same as seeing the color though.
Such animals using sonar can additionally sense density and hardness as well as other material attributes which would cause the acoustic properties of the material as well as movement.
A hard-bodied insect produces a different quality of echo from one with a soft body, so bats can distinguish between some different groups of insects in this way. They can also determine the size of the object.
What's really interesting is that even human beings can experience this unusual sense. Blind people have learned to echolocate by making clicks with their mouth, and there is a movement to teach this skill.
Anyone can try it. In just an hour or two I was able to tell how close I was to a wall, whether the wall was concrete. I couldn't play video games (2:20 on the link) or see colors though.
The following is multiple choice question (with options) to answer.
Echolocation is when animals detect objects by hearing echos using what? | [
"smell",
"vision",
"sight",
"screeching"
] | D | echolocation is when some animals detect objects by hearing echoes by emitting sound |
OpenBookQA | OpenBookQA-3165 | php, mysql, symfony2, doctrine, symfony3
Title: Model database for contract renewal I have made a contract renewal system in Symfony and Doctrine, and it works, but I think it can be improved, but I make too many requests to the database.
These are my models:
Contract
------------
id
reference
....
ContractRenewal
class ContractRenewal
{
/**
* @ORM\Id()
* @ORM\GeneratedValue()
* @ORM\Column(type="integer")
*/
private $id;
/**
* @ORM\ManyToOne(targetEntity="App\Entity\Contract", inversedBy="contractRenewalOld")
*/
private $contractOld;
/**
* @ORM\ManyToOne(targetEntity="App\Entity\Contract", inversedBy="contractRenewalRenew")
*/
private $contractRenew;
/**
* @ORM\ManyToOne(targetEntity="App\Entity\ContractRenewal", inversedBy="children")
* @ORM\JoinColumn(name="parent_id", referencedColumnName="id",nullable=true)
*/
private $parent;
/**
* @ORM\Column(type="datetime",nullable=true)
*/
private $createdAt
The following is multiple choice question (with options) to answer.
What can be renewed? | [
"plastics",
"leather",
"coal",
"diesel"
] | B | a renewable resource can be renewed |
OpenBookQA | OpenBookQA-3166 | botany, reproduction
Most new commercial tomatoes, including new garden tomatoes, are F1 hybrids. The seeds you plant in the field are the result of crossing two parents, as described above. (...) Garden catalogs will tell you whether the seed you are buying is hybrid. If you are getting your fruits from the store, you can count on them being hybrids unless they are marked as heirloom.
The following is multiple choice question (with options) to answer.
If a seed is planted and it develops into a large tomato plant | [
"the seed came from a cucumber",
"the seed came from something red",
"the seed came from a tree",
"the seed came from a bird"
] | B | the type of seed of a plant is an inherited characteristic |
OpenBookQA | OpenBookQA-3167 | electricity, electric-circuits, electric-current
I was wearing flip flops from the time I stripped off my neoprene wet suit at the car until the time I started getting shocked (my wife was wearing Birkenstocks).
I had been snorkeling for about an hour in the Pacific Ocean wearing a full body wet-suit, booties, and gloves (no hood).
I had been camping the night before and consumed quite a bit of Gatorade.
My wife had only been wearing a spring suit and gloves, no booties.
There was another receipt that had been left in the machine (maybe someone else had been shocked as well and decided it wasn't worth the risk of going after it?)
I can't think of anything else relevant. Any insights into what was going on here would be welcome. I tried calling the maintainers of the machine but couldn't get through (this was before I found out that I seemed to be the only one affected).
Thanks!
She tried touching the machine in various places, again nothing. I inadvertently touched her hand while she was touching the machine and then suddenly she felt it too.
From this it is evident you were a good conductor to the ground.
You later say :
We came back out 15 minutes later after drinking our hot chocolate and tried to reproduce the phenomenon with no luck.
So no charge was passing through you any longer?
15 minutes is too little a time to change your conductivity. It could be a combination of an intermittent fault in the circuit and your conductivity at that time. You should alert their maintenance to be on the safe side.
The following is multiple choice question (with options) to answer.
If a thing that was huge and hard is suddenly pooling at your feet, | [
"it is brick",
"it was warmed",
"it is froze",
"it is oak"
] | B | melting means changing from a solid into a liquid by adding heat energy |
OpenBookQA | OpenBookQA-3168 | human-biology, metabolism, toxicology
Title: How does the human body metabolize gasoline? A Chinese man has been drinking gasoline to relieve his pain for 25 years. How does the human body metabolize gasoline? Also, what are the side-affects to gasoline? Just to add an answer to the 'how does the body process gasoline?' portion of the question, the liver and kidney would be doing most of the work of removing the stuff from the system once it was absorbed in the digestive tract.
The liver does most of the processing of toxins and their removal from the blood and would tend to do the most work in removing hydrocarbons from gasoline. It has enzymes that oxygenate toxins (adds oxygens) which make them more soluable in the blood, usually less toxic, and also removable from the body by the liver or the kidney. In the case of gasoline the compounds are likely to be just as toxic.
The kidney works by actively filtering out excess water and mostly water soluable wastes like oxygenated hydrocarbons. Kidney damage occurs when gasoline is ingested in excess. This may be due to the toxicity of the gasoline, but also due to the compounds the liver is producing.
Gasoline will tend to be fat soluable too, so it will leave the system more slowly, even after being processed by the liver (benzene and toluene in gasoline will tend to become phenols which are quite toxic and fat soluable).
http://www.ncbi.nlm.nih.gov/pubmed/3379185
The following is multiple choice question (with options) to answer.
What would be removed via the kidneys? | [
"bacteria",
"organs",
"blood",
"skin"
] | A | the kidney removes byproducts from the blood |
OpenBookQA | OpenBookQA-3169 | newtonian-mechanics, reference-frames, rotational-dynamics, torque
Motor ratings by the manufacturer are merely there to allow you to compare one motor to the next when purchasing them - they are nameplate ratings. I suggest that you not even think for a minute that your motor will always output 40 KGf.CM under all circumstances (including yours). Friction, non-ideal battery conditions, and the like can all give rise to very wide ranges of torque output from your motor. Any calculations you arrive at with the numbers you have will probably not match reality very well. You might consider getting your hands on a variety of motors and experimenting with them.
While we're on this topic, Google can convert KGf.cm into just about any other torque you are more comfortable working in, such as foot-pounds or Newton-meters should that make things easier.
If you want to calculate an estimated minimum torque rating for the motor, you'll need (1.) the mass of the camera and (2.) the distance from the rotation axis to the center of mass of the camera. These two numbers, multiplied together, will give you the minimum torque needed to get the camera heat to begin to rotate.
It is a bit unclear to me what you mean by: ". . .to determine my head capacity when factoring in the height of the camera and it's centre of mass."
Again, I understand your wish to calculate these things before building a prototype, but remember that motor ratings are just estimates - you'll need quite a bit of prototyping and trial and error with motor ratings and torques to find a motor that will overcome the inertia of the camera, but not fling it around so fast as to risk damaging the camera.
The following is multiple choice question (with options) to answer.
if a toy car needed to be measured for its content capacity, which of these might help? | [
"an aluminum coated barometer",
"a metal wind vane",
"a mercury filled thermometer",
"a cylinder with standardized markings"
] | D | a graduated cylinder is a kind of instrument for measuring volume of liquids or objects |
OpenBookQA | OpenBookQA-3170 | visible-light, vision
Title: Explanation about black color, and hence color I'm bit confused about 'black' as a color. As per my knowledge, it is not given in visible color spectra like other colors for example red, violet etc. Also I'm confused with definition of color--does it mean the reflection of respective wavelengths from an object perceived by human eyes or latest electronic sensors determines the color of that object? This is okay for normal people to know that this this color is this this. But how will you tell that some object has Red color to a blind person, how that person can think of that? I can define a bicycle as a vehicle with two wheels, a handle, a seat--this way, a blind person can imagine that vehicle, but tell me the definition of color so as blind person can imagine about specific color considering he/she is blind since birth. Also one more question regarding black--what is the color of an apple if it is placed in a dark room--to eyes, it seems blindly blackish (oh, what the hell this black is again, and why we feel blind in dark places although eyes are open, huh?), but if we focus a torch on that apple with a daylight like color, it looks with original color, why so? The human eye has three types of colour receptors, called cones, that respond to red, green and blue light. Your brain interprets the colour based on the signals from these cones.
For example suppose you're looking at red light. Only the "red" cones will generate a signal and your brain interprets this as red. Suppose now you're looking at a mixture of red and green light. This time the red and green cones generate signals while the blue cones do not, and your brain interprets this as yellow. If there is no light entering the eye none of the cones generate a signal and your eye interprets this as black.
Some colours are pure, that is they consist of light with only a single wavelength, but most colours are mixtures of light with lots of different wavelengths. There are lots of ways scientists measure colour e.g. the RGB system, but actually this turns out to be a surprisingly complicated thing to do because many measurement schemes can't measure all possible colours. Have a look at http://en.wikipedia.org/wiki/Colour for more info.
The following is multiple choice question (with options) to answer.
If a person is blind and needs to know the color of a sign, they | [
"have someone describe it",
"fill out a form",
"are out of luck",
"make a best guess"
] | A | the color of an object can be discovered by looking at that object |
OpenBookQA | OpenBookQA-3171 | wasps
Title: Can wasps see under moonlight? It appears that the best time to attack a wasp nest is in the middle of the night. Their venom might terrorize us (my five-day old sting remains swollen and is starting to have red bumps in an area the size of a tennis ball), but at least our eyesight is superior. If we attack while they are asleep, or at least resting, we have our best chance of escaping unscathed—or so the online pundits claim.
The nest in question is at the edge between the wall and the roof protrusion. Because it is 8 feet off the ground rather than on the ground, it would appear to be a paper wasp nest. But because it is covered with paper and the individual cells are occluded, with the entrance at the bottom the only visible path leading inside, it may well be a yellow jacket nest.
Maybe it's futile to attack the nest in September. One might as well let them be. The nest will anyway be deserted in October when the temperature starts to freeze overnight. But it's never too early to prepare for next Spring.
I could choose a night when there is absolutely no light—not even moonlight—but then I myself would need to use a flashlight, providing them with the means of pursuing me. Or I could choose a full-moon, or near full-moon, night, and then I can see and they can, perhaps, not see.
Can wasps see under moonlight? No.... probably not... wasp cannot see at night... their scotopic vision{dim light vision} is not well develop so before sunset they return back to thier nest... so at night.. probably you can get them all together... rather then hunting for each indivisually...for reference https://sciencing.com/how-to-identify-wasps-bees-13406632.html hope it helps..
The following is multiple choice question (with options) to answer.
How do bats avoid crashing into trees while flying around at night? | [
"they wander around aimlessly lost",
"they bounce their screams off of things",
"they ask someone where to go",
"they see with their eyes"
] | B | sonar is used to find the location of an object |
OpenBookQA | OpenBookQA-3172 | acoustics
It has a lot of mass, too.
If you were to persuade your elephant to lean on a resonant wall, it would damp the wall to some extent, depending on how hard it squished itself against it. It would be acting like the world's biggest lump of rockwool or neoprene rubber. It wouldn't really be fabulously efficient used in this manner.
If, however, we were to replace the wall with entirely elephant, you would very probably have a really, really good sound insulator. 8ft of varying densities & substrates, a lot of mass & not a lot of cohesion between each component & its resonant frequency. If we were to get a bit 'icky' then its lungs & rib cage would probably be the most resonant part - so let's wedge him into the wall facing the noise, & we can sit quietly in the room his butt protrudes into.
Sonic bliss, if not olfactory ;)
Note: I've not even touched on reflectivity or diffusion - that would turn this into a full novel ;))
After comments
It is remarkably difficult to achieve total sonic separation in a domestic environment. I once built a 'room within a room' as a home recording studio, in a house basement, of course surrounded by earth - lots of mass. I did manage to achieve sufficient reduction that you could no longer hear anyone shouting or singing as loud as they possibly could, from the room above. My bass (guitar) amp, however, still went through it like a knife through butter. It took the extra attenuation of the building [double skin of old Victorian brickwork] & earth itself to fully damp it to below audibility. You couldn't hear it from outdoors unless it was particularly quiet in the street.
The following is multiple choice question (with options) to answer.
If a white bear lives in a space and is going to flourish, the space should mostly | [
"match his fur color",
"have a warm climate",
"be dark and humid",
"be green and leafy"
] | A | a polar bear requires a cold environment |
OpenBookQA | OpenBookQA-3173 | The credits of this should go to @rchilton1980. I only want to validate the hypothesis of dispersion as the result of the response of a spike to the finite difference operator.
$$\bf{ Basic \; Theory: }$$
Physical dispersion accounts for the phenomena of waves moving in a way that different frequencies or wavenumbers travel at different velocities. We can make an analogy with a group of cliclist traveling along a flat road at constant speed. Once they hit the mountain it could happen that the heaviest cliclists will ride slower and the group will spread (or disperse) along the road. If we think of a wavelet as the supperposition (synthesis) of many frequencies (and wavenumbers) it could happen that the velocity of each frequency is different. However we need to be more precise on the meaning of velocity here. We define two velocities:
$$\bf{Phase \; velocity}$$
$$$$v_f= \frac{\omega}{k}$$$$
$$\bf { Group \; Velocity: }$$
$$$$v_g= \frac{\partial \omega}{\partial k}$$$$
The previous definitions indicate, in a way, that the angular frequency $$\omega$$ should be a function of the wavenumber $$k$$. That is, $$\omega=\omega(k)$$. To better understand this let us consider the 1D wave equation with constant wavespeed $$c$$.
$$\begin{eqnarray*} \frac{\partial^2 u}{\partial x^2} -\frac{1}{c^2} \frac{\partial^2 u}{\partial t^2} = 0. \end{eqnarray*}$$ If we take a double Fourier transform (from time $$t$$ to frequency $$\omega$$, and from space $$x$$ to wavenumber $$k$$) we find
The following is multiple choice question (with options) to answer.
An example of a disperser could be | [
"Playing outside all alone",
"Running around with my hands in the air.",
"giving out an even amount of Fruit Loops to each of my classmates",
"Taking all the Fruit Loops to myself"
] | C | a disperser disperses |
OpenBookQA | OpenBookQA-3174 | thermodynamics, electricity, dissipation, thermoelectricity
Title: Can a Peltier/Seebeck cell transfer energy from a "thermally insulated" system converting (a part of) thermal energy into electrical energy? Suppose you have a closed system, as per the schema attached below, which walls are thermally insulated.
Suppose you want to reduce the temperature of the fluid inside the closed system, without dissipating 100% of the fluid thermal energy into the environment.
Can a Seebeck cell convert (a part of) the thermal energy of the fluid into electrical energy?
Is the Seebeck cell able to convert a part of the thermal energy into electrical energy (with a given efficiency), or the generation of electrical energy is only a cause of the temperature gradient and this thermal energy will eventually entirely return to the environment thorugh the cell (which, differently from the walls of the system, is clearly not insulated)?
Say, we have a stick of some fitting material. It has some temperature, so all electrons in the material bounce around wildly. Some randomly bounce leftwards; others randomly bounce rightwards. There is no net flow of electrons in any direction. There is no current.
Now, heat up one end. Those now hotter electrons will now bounce around even more wildly. This will make them "fill more space" (more wild random motion means much more pushing on the surrounding particles).
When the electrons "fill more" in one end, there is less "space" there. They start drifting towards the other and still more "spacious" end.
Drifting electrons is a current; electrical energy. This is the essence of the thermoelectric Seebeck effect.
The energy that caused them to move more wildly is directly the thermal energy absorbed at the hot end. They still carry this thermal energy, now in the form of a higher amount of kinetic energy at the micro-scale. So, yes, the Seebeck effect converts thermal energy into electric energy so that there is less thermal energy present - although we are talking about tiny, tiny amounts depending on your situation.
The following is multiple choice question (with options) to answer.
A thermal insulator slows the transfer of what? | [
"warmness",
"light",
"energy",
"liquid"
] | A | a thermal insulator slows the transfer of heat |
OpenBookQA | OpenBookQA-3175 | There is absolutely nothing that prevents the production of a board that is 4in wide; and even if there was, there would be nothing preventing the lumber yard from calling boards that are 3.5in wide '3.5 inch boards'.
The reason why they don't is tradition - it's a hangover from the guild system, wherein the 'mysteries' of the trade are deliberately obscure and confusing, to make it difficult for people who didn't go through the guild apprenticeship system to compete against guild carpenters.
All pre-industrial trades, from carpenters to lawyers, have deliberately imposed barriers to understanding, erected to keep their monopoly.
Of course, there remains some value in the argument that a person who doesn't have enough experience with working timber to know how wide a four inch board actually is, should be discouraged from attempting any serious carpentry work.
But now that the information is so widely available, it seems a bit pointless to keep up this silliness.
Anyone who has ever worked with "rough" lumber will happily pay for a 4 inch board and take a 3.5 board.
In any case, whatever lumber one buys in the US needs to be measured carefully. They may say a sheet of plywood is 96 inches by 48 inches, but it actually cut to the nearest centimeter past 96 and 48.
beero1000
Veteran Member
It's not tool thickness. Dimensional lumber is cut to those dimensions at the mill, then dried and planed. The drying fibers contract and the planing takes off more, so you lose some size.
Excuses, excuses.
There is absolutely nothing that prevents the production of a board that is 4in wide; and even if there was, there would be nothing preventing the lumber yard from calling boards that are 3.5in wide '3.5 inch boards'.
The reason why they don't is tradition - it's a hangover from the guild system, wherein the 'mysteries' of the trade are deliberately obscure and confusing, to make it difficult for people who didn't go through the guild apprenticeship system to compete against guild carpenters.
All pre-industrial trades, from carpenters to lawyers, have deliberately imposed barriers to understanding, erected to keep their monopoly.
The following is multiple choice question (with options) to answer.
Who is most likely to get a job at a lumber yard? | [
"deep sea divers",
"liberal art majors",
"sawyers",
"astronauts"
] | C | timber companies cut down trees |
OpenBookQA | OpenBookQA-3176 | human-anatomy, respiration, health
Is perpetual liquid breathing possible? ...And healthy?
So this is where we stand with the case studies; mice can breath liquids indefinitely and stay in good health, rabbits with ARDS survive where breathable gas would not help, and there is a contingency in the biomedical community that it can be better than gas ventilation for medical treatment. To me it seems that there is nothing to suggest a fully grown adult would suffer from breathing liquids. The inertness of the fluorocarbons implies any toxicity would only reveal itself in a timescale of years, and everything else about the compounds pose no danger and may make gas transfer across the lungs easier.
This relatively modest success is perhaps no surprise. The exchange interface of our lungs relies on a mucous (liquid) so the gases can permeate the lung tissue. Expanding on that idea should certainly not rule out the possibility of liquid breathing.
The biggest drawback, besides the cost of a long term experiment and being dependent on a mechanical ventilator, is that these are very small case studies of success. Given the massive amounts of unknowns (particularly for long term studies), switching to purely liquid ventilation in an adult human could have unforeseen risks and would be considered dangerous by any ethics board (or insurance company)!
On a lighter note, here is a YouTube video of what Maddie, a biology podcaster from the BBC, had to say on the matter of living in total submersion. Lots of skin problems, risk of infection after a few days etc.
Again, a very interesting, albeit understudied, topic!
The following is multiple choice question (with options) to answer.
If someone wants to see if breath is moist, they can | [
"watch some grass grow",
"breathe on a tissue",
"hold in a sneeze",
"look at paint dry"
] | B | breath contains water vapor |
OpenBookQA | OpenBookQA-3177 | audio, filter-design, noise, denoising
I did a quick dirty hack on that and found it sounded already a lot better (although certainly not clean either). Below is a picture that shows the first pulse before and after.
That's work in progress and there are certainly ways to refine this further.
The following is multiple choice question (with options) to answer.
If I wanted to create noise I could | [
"tap a chopstick on a pillow",
"stand completely and utterly still",
"hold in a fart",
"remain completely and utterly silent"
] | A | matter vibrating can cause sound |
OpenBookQA | OpenBookQA-3178 | physiology
Title: Why does dehydration lead to low blood pressure I understand that the two leading causes of death from dehydration is imbalance in electrolytes and loss of blood pressure. I'm trying to understand what role water is playing in these cases and how the loss of it causes these imbalances, focusing for now on the blood pressure angle.
While I understand that blood is made up heavily of water, I'm still a little confused why dehydration so quickly leads to drop in blood pressure. Why can't the body continue to pump the already existing blood through the body, where is it using the water to keep the blood pressure up and what vital function is no longer being performed that causes that pressure to drop? The blood pressure is the exertion of force upon the blood vessels by the blood fluids. Thus having less fluids will results in decreased pressure.
The following is multiple choice question (with options) to answer.
If a person is dehydrated in a desert without water sources like rivers or ponds, they can hydrate by | [
"cracking open peyote",
"staring at sand",
"eating a pebble",
"licking a rock"
] | A | a cactus stem is used for storing water |
OpenBookQA | OpenBookQA-3179 | optics, water, evaporation, gas
Title: How are water vapors not visible? This site says that water vapor isn't visible.
However, take a look at this picture:
Isn't that water vapor? Water vapour is a clear and colourless gas, so it can't be seen by the naked eye.
What you see in the photo in your second link is (partially) condensed water vapour, i.e. fog (or mist). Fog contains tiny, discrete water droplets and light bounces off their surface in random directions, causing the visibility.
Water vapour by contrast only contain free molecules, too small for light to bounce off, so pure water vapour (without any condensate) is invisible, like most gases (some gases are clear but coloured like chlorine gas).
The following is multiple choice question (with options) to answer.
If a high percentage of water is visible in the air? | [
"this is called heat and it is unsafe to drive in",
"this is called fog and it is safe to drive in",
"this is called heat and is safe to drive in",
"this is called fog and is unsafe to drive in"
] | D | fog is formed by water vapor condensing in the air |
OpenBookQA | OpenBookQA-3180 | environmental-chemistry, iron
Title: How is there still iron on earth? Iron rusts and the earth is pretty old, so how is it that there is still iron left that has not oxidized(/rusted)?
I tried looking it up, and the amount of iron on earth is mind boggling, but is that it?
Is there simply enough iron that not all of it has oxidized yet?
Maybe it's just that well insulated inside the crust, or does it occur naturally so more is created all the time? You may confuse iron(1) as an element and iron(2) as the metallic form of iron(1). Rusting of iron(2) does not destroy iron(1), but converts it to iron(1) compounds like non-stoichiometric hydrated oxides.
Iron(1) of Earth is much older than Earth and the Solar system. But most of surface iron(2) is less than 100 years old. All but the one contained in rare meteorites was produced by men from iron(1) ores.
Iron(1) in Earth's mantle and Earth's crust occurs in oxidized forms in various minerals, ores and rocks. E.g. the primary mineral of Earth upper mantle is olivine $\ce{(Mg, Fe)2SiO4}$
There is also iron(2), together with nickel, in Earth core, at high temperature and extreme pressure, where is no rusting.
The following is multiple choice question (with options) to answer.
Iron can be found on | [
"rocky areas",
"ants",
"wizards",
"unicorns"
] | A | rocks sometimes contain iron |
OpenBookQA | OpenBookQA-3181 | infection, amphibians
Title: What is this toad suffering from? Myiasis or chytridiomycosis? I found this toad on Aug. 29th at this location: position on osm
I think it is a bufo bufo, approx. 10 cm long. The nostrils seemed to be completely filled with a grey matter and from the activity of the floor of the mouth it apparently tried to breathe againgst this obstruction. It probably had enough oxygen via its skin though.
I tried to remove the obstruction using a blade of grass but this seemed to produce some pain as the toad closed its eyes on contact, so I stopped. The skin looked fairly normal and the toad was able to walk away after a while.
I can think of two causes for this condition.
Batrachochytrium dendrobatidis infestation
Lucilia bufonivora larvae
I could not see properly, if there were any larvae or unhatched eggs inside the nostrils, but as the rest of the skin seemed unharmed I assume the latter.
Is my assumption valid or is there even a third possibility? It is a female Bufo Bufo and you are right, there are toad fly (Lucilia bufonivora) larvae/eggs inside her nostrills. These flies lay their eggs inside toads' nostrills (specifically on Bufo Bufos) and the larvae start eating them. Sadly this disease ends up by the death of toad. They slowly eat nostrills, then mouth, eyes, and all the head.
Here's a photo of a male bufo bufo, without a head. Someone found it walking around at this situation. https://i.stack.imgur.com/I6twl.jpg
The following is multiple choice question (with options) to answer.
A person with a pet amphibian will likely feed it | [
"meal worms",
"deer",
"steak",
"wax"
] | A | a frog eats insects |
OpenBookQA | OpenBookQA-3182 | electromagnetism, experimental-physics, kinematics, magnetic-fields
Title: What is quartz, and how does it work in watch and electronic circuits? How does it helps in watch and electronic circuit broad?
Is there any material to refer? Quartz is silicon dioxide (SiO2); the crystal form called 'alpha-quartz'
is a hexagonal crystal (which you have probably seen, because it is a
common and rather attractive mineral). In that crystal form, the
application of stress will slightly polarize the material (cause electric
charge to move), and the inverse effect also holds (electric charge applied
to the crystal will cause it to change shape).
The final piece of the puzzle, is that quartz is acoustically 'live', i.e.
it rings like a bell. Like a bell, the acoustic pitch depends on shape
and size, so it can be shaped and sized for a
wide range of different frequencies of oscillation.
A sculpted piece of crystal can be used in an oscillating electric circuit to selectively
generate an accurate frequency. Tuning of radios was an early application, and many others followed. Networked data, like radio, requires accurate timing at multiple locations. Clocks, too, benefit from the mass-production of time standards in quartz crystal form.
The following is multiple choice question (with options) to answer.
A quartz crystal is a transparent | [
"magic producer",
"power source",
"deodorant",
"hexagon"
] | D | a quartz is made of six-sided transparent crystals |
OpenBookQA | OpenBookQA-3183 | botany, reproduction
Most new commercial tomatoes, including new garden tomatoes, are F1 hybrids. The seeds you plant in the field are the result of crossing two parents, as described above. (...) Garden catalogs will tell you whether the seed you are buying is hybrid. If you are getting your fruits from the store, you can count on them being hybrids unless they are marked as heirloom.
The following is multiple choice question (with options) to answer.
A person who plants in their garden may switch between planting beets and cucumbers in order to | [
"clean up dirt",
"make dirt healthier",
"remove dirt molecules",
"make dirt green"
] | B | crop rotation has a positive impact on soil quality |
OpenBookQA | OpenBookQA-3184 | Tourist Places In Coimbatore Near Gandhipuram, Sunrunner Pembroke Welsh Corgis, Where Is Serana In Fort Dawnguard, Hello Etch A Sketch Font, Monkey King Characters, Adam Bradley Amazon,
The following is multiple choice question (with options) to answer.
Where is the best place to shoot animals? | [
"national park",
"sky",
"sea",
"forest"
] | D | national parks limit hunting |
OpenBookQA | OpenBookQA-3185 | special-relativity, visible-light, speed-of-light, aether
One consequence of a finite $c$ is that it stops a causal chain of events spread throughout space from happenning all at once. An infinite $c$ would mean that events here on Earth could provoke other events instantly in the middle of M87, and this is not what is observed to happen.
The following is multiple choice question (with options) to answer.
which of these days would lead to a suspension of regular activities? | [
"a very sunny day",
"a very beautiful day",
"a very bright day",
"a day with a blizzard"
] | D | snowy means a large amount of snow |
OpenBookQA | OpenBookQA-3186 | meteorology, climate-change, gas, pollution
If you are interested in Greenhouse Gases (e.g. methane, carbon dioxide, CFCs, nitrous oxide), the EPA has a separate site for those emissions since they are not part of the same regulatory framework http://www.epa.gov/climatechange/ghgemissions/ . Greenhouse gases typically do not cause adverse health effects for plants or animals on land. However, they have long-term radiative effects (e.g. the greenhouse effect) because they stay in the atmosphere for many years and trap infrared light. These long-term radiative effects are what can change climate and consequently land cover. Furthermore, most of the excess carbon is absorbed by the ocean, which creates carbonic acid. Increased acidity of the ocean causes severe problems for marine ecosystems.
The EPA states that in 2012 the CO2 equivalent GHG emissions for the USA by sector was:
The following is multiple choice question (with options) to answer.
One of the main things that can negatively impact organism health is | [
"singing",
"nothing",
"walking",
"falling ill"
] | D | illness has a negative impact on an organism 's health |
OpenBookQA | OpenBookQA-3187 | 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.
Where might you find some animals being held outside of nature? | [
"under the deep sea",
"up into the sky",
"deep into the earth",
"artificial habitats in captivity"
] | D | some animals live in zoo exhibits |
OpenBookQA | OpenBookQA-3188 | botany, microbiology, terminology, etymology
Title: Rhizosphere vs. Endorhiza? In relation to microbiology and the naming of the various areas of the plant as it relates to microbial inhabitance, I am confused as to the difference between the terms endorhiza and rhizosphere.
In this case I see rhizosphere referred simply to as the 'roots', but in this case I also see endorhiza explained simply as 'roots' also.
However in this case, I see a further explanation for endorhiza (which does make sense etymologically): 'internal root tissues'.
Does this mean endorhiza is be a sub-term for the area inside the roots, and the larger area of the rhizome in general represented by rhizosphere, and that is the difference? Healthy plant growth depends on a microbial community that lives around and inside the roots of plants (Bais et al. 2001). Roots secrete from the roots a number of chemical compounds that influences the microbial community around but outside of the roots. The microbial community can include bacteria, fungi, and single-celled parasites, as well as larger organisms like insect larvae and even roots from other plants. Some chemicals attract certain organisms while other chemicals repel organisms. This community of organisms around the roots is called the rhizosphere (Walker et al. 2003). The paper by Walker (open access) describes some of the many types of symbiotic relationships that occur in the rhizosphere.
Endorhiza refers to the internal environment of the root system. The endorhiza contains another microbial community of bacteria and fungi (Backman and Sikora 2008). The organisms of this endorhizal community are collectively called endophytes. Like the rhizosphere, the organisms in the endorhiza are important symbiotic species that benefit the health of the plant.
Similar communities have been identified for other regions of the plant, such as the phyllosphere, the organisms that live on the leaves, stems and other plant parts above the ground (Backman and Sikora 2008).
The following is multiple choice question (with options) to answer.
What anchors plants into the soil are called | [
"a form of webbing",
"Velcro with extra grip",
"the same as an american television miniseries about slavery",
"large anchors made of metal"
] | C | roots anchor plants into the soil |
OpenBookQA | OpenBookQA-3189 | human-biology, reproduction, human-anatomy, temperature
Title: Scrotal temperature and vascularization The testes (at least in human males) are vascular organs, the vascularization extending even o the interstitial spaces of the seminiferous tubules. The function of the scrotal sac, is to isolate the testes from the abdominal cavity, and provide a lower temperature ($1-2^\circ \text C$ lower than normal body temperature of $37^\circ \text C$).
But since the blood is the main temperature-buffer maintaining the
normal body temperature and the scrotal (testicular) tissues are
considerably vascularized, why doesn't the blood flow raise the
scrotal temperature to normal body temperature?
If the reason is the location of scrotum external to the abdomen, then all limbs and limb-extremities are located in the similar way (and in those cases, heat dissipation would be faster than in case of scrotum due to less surrounding insulation by thighs and clothes), and hence the temperature of all parts except the interior of the head and abdomen must be at considerably lower temperature? Is this the case? The fingers and toes (for example) ARE at lower temperatures than the interior of the torso. It's why it's so easy to get frostbite on the extremities. As for temperature regulation of the testes, you have to also consider that humans evolved without clothes...i.e. The testes just "hang out" and get lots of airflow, as opposed to modern times, when they are typically under (usually) more than one layer of clothing.
Also, for reference, I took some quick IR temp readings on myself:
Room temp: 19.9C
Fingertip: 27.0C
Palm: 31.8C
Axilla: 34.6C
The following is multiple choice question (with options) to answer.
Hotter blood is rarely found | [
"in horny toads",
"in rats",
"in humans",
"in bears"
] | A | a reptile is cold-blooded |
OpenBookQA | OpenBookQA-3190 | newtonian-mechanics, energy-conservation, friction, everyday-life, physical-chemistry
Title: Conservation of energy when we drive a car When we drive a car, we use gasoline as the source of energy. When we arrive at the destination, we lose some of the gasoline, used to move the car from one point to another. Then how energy is conserved, if we spend energy to move the car? What does it mean to "spend energy"? In the concrete example, the engine converts the chemical energy in the gasoline through combustion into kinetic energy of the car.
While the car is moving, it feels friction with the surface and air, so some of the kinetic energy of the car goes into friction (heat, air movement, etc).
When you stop the car, the kinetic energy completely goes into friction in the brakes, asphalt and air (again, as heat or kinetic energy of the air molecules, etc).
Conservation of energy means that in a closed system the energy stays constant. If you look just at the car and not also at the surroundings, that is not a closed system, and that principle is not applicable here. However, you can look at the surroundings too; then it all works out.
The following is multiple choice question (with options) to answer.
A car running on a resource that will someday cease existing uses | [
"dino remains",
"water power",
"solar power",
"electricity"
] | A | natural gas is a nonrenewable resource |
OpenBookQA | OpenBookQA-3191 | zoology, ethology, behaviour, psychology, death
I can't prove it to you, but I know that my Beagle had a rich emotional life. I know this because I spent huge amounts of time with him. He was a close friend of mine. I would just as soon question whether my wife has real emotions as my dog. I can't prove that my wife's emotions are real either, but I don't have to. It would be silly to assume that everything she shares with me is some sort of evolutionary programming, and not real emotion. Now, when I extend this to cetaceans, I must admit that I don't have any friends in those circles. So I can only guess.
The following is multiple choice question (with options) to answer.
Bringing a stray dog to live at your house when it lived outside all its life will be hard for it at first, but eventually, it will | [
"fly away",
"start talking",
"get acclimated",
"tell jokes"
] | C | animals adapt to their environment |
OpenBookQA | OpenBookQA-3192 | 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 person is making laps around a gym, they find that | [
"they are about to be born",
"they are gaining weight",
"their heart starts racing",
"they are getting fatter"
] | C | as energy required for an activity increases , pulse will increase |
OpenBookQA | OpenBookQA-3193 | 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.
I found an impression of bird's feet in a rock | [
"monkeys carved the footprints into the rock",
"the rock is made of soft mud",
"a very heavy bird was walking on the rock",
"the substance that was walked in became hard after a very long time"
] | D | An example of a fossil is a footprint in a rock |
OpenBookQA | OpenBookQA-3194 | botany, terminology, fruit
Title: What is the name of this part in plants, fruits, vegetables? What is the name of this part of the plant, fruit, vegetable? The thing that the plant is connected with the tree and gets nutrients with? The part we usually cut out when eat fruit.
Examples below
Papaya
Banana
Mango 'Stalk' or 'pedicel' would be an appropriate term (see, for example, this paper or this one). Specifically, you could say 'terminal part of the stalk/pedicel', though I don't know if there is a word for that.
Note that the term pedicel is commonly used for the stalk of a flower; it makes sense to use it for fruits too as they are derived from flowers.
The following is multiple choice question (with options) to answer.
What are the source of fruit? | [
"wood",
"plant diagrams",
"green life",
"housing"
] | C | plants are the source of fruit |
OpenBookQA | OpenBookQA-3195 | combustion, temperature, fuel
Of course a lot of other factors are involved but this crude picture gives at least some useful insight. This was discovered experimentally in the early days of engine design as the designers observed that different extracts from oil had different combustion properties in engines and refined the way oil was distilled to give them the behaviours they wanted in their engines.
The following is multiple choice question (with options) to answer.
What is oil likely comprised of? | [
"homo sapiens",
"air",
"soil",
"brontosaurus"
] | D | fossil fuels are formed by dead organisms over time |
OpenBookQA | OpenBookQA-3196 | mechanical-engineering
Title: How to Make an Object Able to be Screwed In/Out With a Sideways Knob I am trying to make a device that can go up or down a screw by twisting a knob, kind of like a wing nut, but the wing would be sideways (I suppose). To clarify what I mean by this, please see a simplified version in a diagram below.
I think this type of engineering has already been used in various devices, such as a microscope, where the course adjustment knob will raise or lower the "stage" of the microscope.
Does anyone know where a part/device like this could be found, or how I would go about making something similar?
Thank you so much for your time and kindness,
Kelsey Nealon I can't see a worm gear working in this instance as it would be trying to reverse drive the worm - there is too much friction to achieve this. A rack and pinion would not stay in place after releasing the knob.
You could use a 90 degree bevel gear with an internal thread in the output gear like the one in the photo.
The following is multiple choice question (with options) to answer.
A simple machine like a screw will need | [
"a glass of cool water",
"a person adjusting it",
"a truck to move it",
"a wind turbine to function"
] | B | a simple machine requires mechanical energy to function |
OpenBookQA | OpenBookQA-3197 | acoustics
Title: Amplified Sound in another room I was sitting in my room with my door open, because I have a cooler in my room that has a lot of noise when turned on. I was watching a video on my phone, but because of the noise from the cooler, I couldnt hear it and I had to increase the volume. However, my brother comes from the adjacent room and tells me he can hear the sounds from my phone very clearly and loudly, although his door was closed. I cant seem to understand this phenomenon. How can he hear sounds from my phone clearly, when I myself cant hear it clearly due to the cooler? Several reasons are at work here, as follows.
First, if the cooler fan is closest to you, then you will be bothered by it more than your brother, who is farther away.
Second, the noise made by a cooler fan is well-blocked by walls and doors, whereas music and speech is less-well blocked.
Third, random noise (as from a cooler fan) is fundamentally less bothersome than speech and music, to which your hearing "software" is far more sensitive.
A practical application of these effects is called masking, where the sound system speakers in a busy, open office are fed a random whoosh noise which renders speech in an adjacent cubicle inaudible to you. In fact, after several days in such an office, you get used to the whoosh noise coming from the speakers and you stop hearing it altogether. The office seems to your ears to be perfectly quiet, even though it is not!
The following is multiple choice question (with options) to answer.
If sound is moving around in a room, the room is lacking in | [
"atmosphere",
"vacuum",
"oxygen",
"air"
] | B | air is a vehicle for sound |
OpenBookQA | OpenBookQA-3198 | electromagnetism, electricity, energy-conservation, perpetual-motion
Title: Auto spinning turbine generator This might be dumb question but I'm so curious to know if this actually works or is impossible. I was researching how you could generate electricity from magnets and copper wire and also have read how the hydroelectric generators work and it seems like they share the same concept. So if we are able to generate electricity by moving the turbine with water then why not have a some sort of motor which will make the turbine spin by getting power from the generator. I mean first there needs to be some sort of initial mechanical source to make the turbine spin then once the turbine starts moving and the generator gives power, the other motor gets power and it will take over the spinning of the turbine. So that way it will auto spin itself and basically means free energy. Can someone explain why this is not possible? As with virtually all perpetual motion machines, the reason becomes obvious once you consider the thermodynamic efficiency of the components involved. No turbine is 100% efficient, and also no motor is 100% efficient. This means that out of the initial energy you put in to make the turbine spin, only a certain percentage will be converted to electricity, with the rest being converted to heat. Then, out of that electricity, only a certain percentage is converted to mechanical energy to drive the turbine again. Then we go round again, losing some of that energy to heat until pretty soon the whole thing stops turning.
Of course, it would work just fine if you had an engine or a turbine that was more than 100% efficient, putting out more energy than you have to put in to drive it. But then, that's exactly the reason why we know that efficiencies over 100% are impossible: we observed that perpetual machines seem to be impossible, and from that Carnot derived his thermodynamic limits. The resulting theory has stood the test of time since the 19th century.
The following is multiple choice question (with options) to answer.
A windmill just uses the air around it, nothing unnatural. Because of this, everything they produce is | [
"unpolluted",
"candy",
"Grapes",
"dirty"
] | A | a windmill does not create pollution |
OpenBookQA | OpenBookQA-3199 | 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.
If a plant is moved from a basement to a field | [
"it will need darkness",
"it will be too dark",
"it will receive nutriment",
"it will now suffocate"
] | C | if something is outside during the day then that something will receive sunlight |
OpenBookQA | OpenBookQA-3200 | genetics
Additional response added as requested:
I see what you are getting at - why do children seem like such individual and unique things sometimes?
In sexual reproduction, the offspring are the product of the shuffling of the parent's genomes through meiosis, where the pairs of chromosomes we have are combined to make a single chromosome that will be half of the children genome.
This process can result in completely novel combinations of genes while conveying many likenesses from the parent. I would guesstimate that this is the major cause of the uniqueness of offspring/children.
Also in mammals there are some cell lines which splice families of genes which will cause offspring to be potentially quite different from either parent. Immune genes for instance are created from scratch from a bunch of genes that the parents give. Making each offspring unique but also the product of the parent's genetic repertoire. This can be significant as it affects health and also to some extent attraction - studies have shown that people who smell attractive to us are immunologically distinct from us.
@David mentions epigenetic variation, which is a more recent significant development. During our life, the germline (sperm/egg) DNA may be chemically labelled depending upon environmental conditions we experience. A famous example is experiencing famine conditions, which caused the children to be born on the small side amongst other effects. More recent studies have shown that this is a widespread mechanism to control cells in our body during our lifetime as well as communicate to our offspring how life is. It is expected that this labeling does not affect us forever - the epigenetic labels change over the course of a generation quite often (we believe).
The following is multiple choice question (with options) to answer.
Reproduction means a development of genes like | [
"time travel",
"a personality",
"magical powers",
"hairline"
] | D | living things can all reproduce |
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