source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-2201 | However, this includes the solution when $$x_1,x_2,x_3,x_4,x_5=0$$, which is explicitly stated in the problem to be excluded. Hence our final answer is $$\boxed{6187}$$.
Questions like this are often worded ambiguously, forcing you to figure out a sensible interpretation. In this case, you aren't told whether different balls of the same color should be considered different when counting "ways". However, if we considered same-colored balls distinct, then the colors would be irrelevant (and since the number of balls is "unlimited", we wouldn't have enough information to answer the question). So we can infer that you're expected to think of two handfuls as the same if they look the same (e.g. "5 red and 4 blue"), even though multiple different sets of balls might look the same way.
The "unlimited" here just means that it's possible to get a handful where all balls are the same color (of any color). Since we're only interested in handfuls of at most 12 balls, it doesn't matter whether the box has 12 of each color or 100 of each color.
In other words, you're looking for the number of non-negative integer solutions to
$$x_1+x_2+x_3+x_4+x_5\le12$$
and the "unlimited" means there are no explicit upper limits on the variables.
The following is multiple choice question (with options) to answer.
A person needing to know if a ball is orange or turquoise can decide by sparing it a | [
"meal",
"thought",
"dollar",
"peek"
] | D | the color of an object can be discovered by looking at that object |
OpenBookQA | OpenBookQA-2202 | evolution, species
Title: Parents that eat their own children I am told that there are some species, like fish or rabbits, that if let, will eat their own children. If this is true, how does a species like this exist? Shouldn't the fact that they kill their own lineage make them nonviable? Yes, it is true.
Prairie dogs
Prairie dogs for example are known for frequent infanticides.
Many other species kill their babies too
But of course, such behaviour also exists in other lineages such as grey langurs, gerbilles, lions, giant water bugs and Bottlenose dolphins (just to cite a few examples).
How does that evolve
It will be impossible to provide a complete universal explanation to this behaviour because the evolutionary processes causing this behaviour varies from lineage to lineage. For examples, in lions, only males kill young of the females that are still nursing and they do so when taking over a new harem only. In prairie dogs, mothers cause infanticide preferentially on others' babies but also on their own babies.
Going into the details of how such behaviour evolves in every specific lineage would probably require writing an intro on kin selection and other fields of evolutionary biology which is way too much for a single post. You may want to have a look at the wikipedia article infanticide for a start.
Shouldn't the fact that they kill their own lineage make them nonviable?
Of course, they don't kill all the babies. Only a fraction of them!
The following is multiple choice question (with options) to answer.
A barracuda will be able to raise its own offspring because | [
"it is troubled",
"it is hairy",
"it is hungry",
"it is alive"
] | D | living things can all reproduce |
OpenBookQA | OpenBookQA-2203 | species-identification, ornithology
Why would a mother do that to her young? Does she hates the little one? Not at all. It’s just that those little birds were made to fly, and they don’t know it, so she is going to push them out of the nest. She never lets them hit bottom, but she does let them fall, because they have to learn something they don’t know.
The next time the mother bird comes back she decides to clean house, and so she stands on the edge of the nest. The first things to go are the feathers inside; she drops them over the edge. Then the leaves go over the edge—heave ho! While this is going on, she’s not very talkative, either. ("Mom, what are you doing?") She pays no attention. Since she built the house, she knows how to take it apart.
Next she decides to take the sticks out of the middle of the nest, and with her great strong beak and feet, she’s able to break them off and stand them straight up. ("Mom, it’s not comfortable in here anymore.") Then she takes certain key sticks out of the nest and throws them over the edge. ("What are you doing, Mom? You are wrecking my room.")
She seemingly pays no attention to the concerns of her young as she prepares to pull the nest apart, for she is determined that those little ones will fly, and she knows something they don’t. She knows they will never fly as long as they remain in the nest.
The following is multiple choice question (with options) to answer.
A hatched chick will know how to construct a nest when it needs to because it is | [
"instinctual",
"considerate",
"learned",
"a given"
] | A | an animal knows how to do instinctive behaviors when it is born |
OpenBookQA | OpenBookQA-2204 | h. Evaluate C.
i. Compute Q(7), the amount of glucose produced during the day.
Exercise 10.3.5 “Based on studies using isolated animal pancreas preparations
maintained in vitro, it has been determined that insulin is secreted in a biphasic manner in response to a marked increase in blood glucose. There is an initial burst of insulin secretion that may last 5-15 minutes, a result of secretion of preformed insulin secretory granules. This is followed by more gradual and sustained insulin secretion that results largely from biosynthesis of new insulin molecules. ” (Rhoades and Tanner, P 710)
a. A student eats a candy bar at 10:20 am. Draw a graph representative of the rate of insulin secretion between 10:00 and 11:00 am.
b. Draw a graph representative of the amount of serum insulin between 10:00 and 11:00. Assume that insulin is degraded throughout 10 to 11 am at a rate equal to insulin production before the candy is eaten, and that serum insulin at 10:00 was Iq.
CHAPTER 10. THE FUNDAMENTAL THEOREM OF CALCULUS
468
c. Write an expression for the amount of serum insulin, I(t), for t between 10:00 and 11:00 am.
Exercise 10.3.6 Equal quantities of gaseous hydrogen and iodine are mixed resulting in the reaction
which runs until I 2 is exhausted [H 2 is also exhausted). The rate at which I 2 disappears is ^°’^ 2 gm/sec. How much I 2 was initially introduced into the mixture?
a. Sketch the graph of the reaction rate, r(t) = jp^yi-
b. Approximately how much I 2 combined with H 2 during the first second?
c. Approximately how much I 2 combined with H 2 during the second second?
d. Let Q(x) be the amount of I 2 that combines with H 2 during time 0 to 2; seconds. Write an integral that is Q(x).
e. What is Q\x)l
f. Compute W'{x) for W(x) = =^.
g. Show that there is a number, C, for which Q(x) = W(x) + C.
h. Show that C = 0.2 so that Q(x) = 0.2 – g.
The following is multiple choice question (with options) to answer.
CO2 is released into the air when sugar eaters | [
"sigh",
"touch",
"think",
"consider"
] | A | an organism breaking down sugar is a source of carbon dioxide |
OpenBookQA | OpenBookQA-2205 | anatomy, scales
If this horse is 500 kg (a mid-range mass for horses), each leg would have to support 125 kg, compared to only 37.5 kg for a 75 kg adult. Why don't we see a corresponding difference in cross-section? Elephant, rhinoceros, &c all have much thicker legs in proportion. The answer, I think, lies in the fact that the animals you mention all evolved as cursorial animals (that is, they run to escape predators). Less mass in the lower leg means it swings easier, so the animal can run faster.
There are two things you're apparently not noticing in that picture. First, the the horse's lower leg is almost entirely bone (and some tendon), and it's bone that does the supporting. The propulsive power comes from the large muscles of the hip, thighs, and shoulders.
Second, the lower part of the leg (with the white wrappings) is not anatomically equivalent to the human's lower leg, but to the bones of the hand and foot. You can see this if you look closely at the rear leg in that picture. The femur, equivalent to the human's thigh, ends at the knee just above the belly line. Then the tibia extends about halfway down, ending at another joint which you might think is the knee, but which is called the 'hock' in horse-speak. The white-wrapped part is a metatarsal, equivalent to human foot bones, then there pastern bones equivalent to human toe bones, ending in the hoof/toenail.
So consider that you can, if reasonably fit, walk around on tiptoe without crushing your foot and toe bones, then imagine the end result of your ancestors having done this for the last several tens of millions of years :-)
PS: With horses, there is some effect from human selection, too. Racing & show breeds tend to have thin lower legs, draft horses & working breeds have proportionately thicker ones. My first horse, a thorobred/arab mix, had legs about as thick as my wrists (granted, I'm a fairly muscular guy); my current mustang, about the same height & weight, has legs about twice as thick.
The following is multiple choice question (with options) to answer.
A dog's ears may be as thin as its | [
"friend's",
"neighbor's",
"father's",
"owner's"
] | C | the thickness of the parts of an organism is an inherited characteristic |
OpenBookQA | OpenBookQA-2206 | c#, .net
...
KickCat(new MuteCat()); // I love this cat, it's like it doesn't even care!
KickCat(new LoudCat()); // Whines, blah.
KickCat(new StrangeCat(true)); // Whines this time.
KickCat(new StrangeCat(false)); // Doesn't whine this time! Woot!
The following is multiple choice question (with options) to answer.
Every hour, the tiny kitten cried for milk. It was true that | [
"the kitten was a year old",
"the kitten wanted meat",
"the kitten didn't need milk",
"the kitten wanted milk on a regular cycle"
] | D | a cycle occurs repeatedly |
OpenBookQA | OpenBookQA-2207 | electric-circuits, home-experiment
Title: Why does this circuit work and the other doesn't?
if we connect the set up like this the bulb glows but if we connect the [right wire] to the [earth of the left] then the bulb [doesn't glow].
Why does that happen?
if we connect the set up like this the bulb glows
If the pin positions in the photo are
Ground
Neutral Line
And you are in a country where
the neutral is linked to ground at the main panel
but where protective devices such as GFCI or RCD are not used.
Then you have a path for current to flow from Line via Ground to Neutral.
if we connect the [right wire] to the [earth of the left] then the bulb [doesn't glow].
Connecting to the ground of the left socket instead of the ground of the right socket should produce the same result if the socket is wired correctly.
The fact that it doesn't light the lamp suggests either that you made an error in your improvised unsafe connection (the connectors inside those sockets are designed for use with solid metal pins with a specific range of dimensions, not for poking stranded wire into) or that
your socket is badly designed, badly manufactured, badly installed or is damaged. The two ground connectors are not properly connected together internally.
To verify this you could carry out a ground loop impedance test using a suitable Category-II test instrument (isolate the circuit line conductor first using circuit breakers or equivalent at main panel).
The following is multiple choice question (with options) to answer.
Why would a lightbulb be dark? | [
"the bulb needs to be charged",
"the room is too bright",
"the circuit is incomplete",
"it ran out of electricity"
] | C | electricity can not flow through an open circuit |
OpenBookQA | OpenBookQA-2208 | visible-light, sun, weather
Title: Why are clouds lighter than the sky during the day but darker at night This is probably a very basic question but I couldn't find a good answer to it, most search results are about rain clouds or clouds appearing red at night (something I've never seen except for during sunset but apparently it's common in bigger cities).
Basically what I'm wondering is why clouds during the day appear lighter than the sky (white vs light blue) while clouds at night and during the evening appear darker than the sky (see image).
Image quality is low because I took it with my phone through my window.
I guess the clouds could be blocking the light and therefore appear darker but in that case, shouldn't the same thing be happening during the day? There could be quite a few things going on.
Off the bat there's no incoming light for them to scatter: during the day, clouds are white because the water droplets are big enough for all visible light to cause Mie scattering, but if you don't have much light falling on them, you can't observe the scattering and you can't observe light passing through either.
Then you could consider the fact that in some places, it rains more in the evening/night than during the day (if you have hotter surface temperatures during the afternoon, you see cloud formation and precipitation during the late evening, and with the lower temperatures in the night, the air is more likely to become saturated, see Dew Point), and clouds which precede rain are thicker and denser. They don't allow much light pass through.
And lastly, there's less ambient light which they can reflect back towards you.
The following is multiple choice question (with options) to answer.
After dark clouds roll in and the weather changes, clouds may | [
"wilt",
"precipitate",
"burn",
"zap"
] | B | An example of stormy weather is rain |
OpenBookQA | OpenBookQA-2209 | 4. A contractor estimated that his 10-man crew could complete the construction in 110 days if there was no rain. (Assume the crew does not work on any rainy day and rain is the only factor that can deter the crew from working). However, on the 61-st day, after 5 days of rain, he hired 6 more people and finished the project early. If the job was done in 100 days, how many days after day 60 had rain?
(C) 6 - rains for 5 days from day 56-60. So 10 guys worked for 55 days and accomplished half of the work. If 6 more guys are added to the job then the rate is 16/1100. (since one man's rate is 1/1100). Half the job left means 550/1100 is left. Therefore 550/16 = 34.375 days of more work. Since there were 40 days between day 60 and job completion, it must've rained for 40-34.375 = 5.625 or ~6 days. (I'm not sure if this is correct)
5. If s and t are positive integer such that s/t=64.12, which of the following could be the remainder when s is divided by t?
(E) 45 - 64.12 = 6412/100 or 1603/25. 1603/25 gives a remainder of 3, 3206/50 gives remainder of 6 and so on ..pattern = factors of 3. so to get remainder of 45, we multiply everything by 15: 1603*15/(25*15) = 24045/375.
The following is multiple choice question (with options) to answer.
A bucket full to the brim with water is left outside. If the day is warm, by the end of the day, the bucket will be | [
"wood",
"gone",
"full",
"emptier"
] | D | if a liquid disappears then that liquid probably evaporated |
OpenBookQA | OpenBookQA-2210 | Live Urban Brown Before And After, Excel Vba Create Pivot Table With Data Model, Waterproof Ipad Mini 4 Case, Double Trough Sink, Basic Warehousing Procedures, Temporary Wheelchair Ramp Rental, Will Frontline Still Work If My Cat Licks It, Text Detection In Images, Door Lever With Push Button Lock,
The following is multiple choice question (with options) to answer.
An ivory page will be able to | [
"feed a family",
"make some money",
"reflect all light",
"eat a cookie"
] | C | a white object reflects all visible light |
OpenBookQA | OpenBookQA-2211 | gravity, water, space, planets
The only detail left is how to get a surface temperature that's in the right range for the surface to be liquid. This depends on the distance from the star, but also on the composition of the atmosphere. On Earth, the atmosphere's composition is mostly due to the action of the biosphere, which keeps the temperature regulated in just the right range for water to be liquid. Perhaps it's possible to imagine life on such a water world, in the form of photosynthesising algae-like organisms, which might play a similar role.
The following is multiple choice question (with options) to answer.
On a wet planet, the amount of seas will | [
"be dwarfed by land",
"outnumber amounts of land",
"be less than land amounts",
"be smaller than land"
] | B | oceans cover 70% of the surface of the earth |
OpenBookQA | OpenBookQA-2212 | python, beginner, game, functional-programming, adventure-game
winter = '\n' + '''29 January 2029. It is five weeks into winter and the season shows no mercy. A drought happened for a majority of the last fall and it devastated
the food supply. As your community dives deeper into the winter, you realize that your supply will run out if consumption is not altered. You could do one of two options: reduce
consumption among civilians, or ignore the risk and take a chance([ALTER SUPPLY]X} {B[IGNORE RISK]).''' + '\n> '
alter_supply = '\n' + '''Your government is now seen as selfish. You took the risk to protect the important people and "do your best with the rest". You have suffered heavy
civilian losses but your army and government losses have been few. As a result, there is division and danger in the streets. Riots breaking out, murders, arson, all happening in
your community.''' + civil_great_decrease
ignore_risk = '\n' + '''Your community did better than expected during the period. That is until you ran out of food in early March. Now you rely solely on scavenging,
risking getting devoured by zombies in order to go another day. Half your community is either dead or lost with great amount of casualties from civilians and
non-civilians.''' + army_great_decrease
The following is multiple choice question (with options) to answer.
A person wanting to harvest tomatoes in the harshest winter in decades could do so if they obtained a | [
"snowblower",
"shovel",
"underground pool",
"heat lamp"
] | D | a plant light is used for help plants by mimicking sunlight |
OpenBookQA | OpenBookQA-2213 | java, repository
unlink(node);
linkLast(node);
}
private static class Node<K, V> extends SimpleEntry<K, V> {
private static final long serialVersionUID = 1L;
private Node<K, V> prev = null;
private Node<K, V> next = null;
private long expirationTime;
private Node(K key, V value, long liveTime) {
super(key, value);
updateExpirationTime(liveTime);
}
private Node(Node<K, V> prev, Node<K, V> next, K key, V value, long liveTime) {
this(key, value, liveTime);
setLinks(prev, next);
}
private void setLinks(Node<K, V> prev, Node<K, V> next) {
this.prev = prev;
this.next = next;
}
private long timeTillExpiraton() {
return expirationTime - System.currentTimeMillis();
}
private boolean isExpired() {
return expirationTime - System.currentTimeMillis() <= 0;
}
public void updateExpirationTime(long liveTime) {
expirationTime = System.currentTimeMillis() + liveTime;
}
}
private static class Cleaner<K, V> implements Runnable {
private ExpiringKeyValueRepository<K, V> rep;
private boolean stopped = true;
private Lock writeLock;
private Condition checkCondition;
private Cleaner(ExpiringKeyValueRepository<K, V> repository) {
this.rep = repository;
this.writeLock = repository.writeLock;
this.checkCondition = repository.checkCondition;
}
@Override
public void run() {
writeLock.lock();
try {
while (!stopped) {
while (rep.first != null && rep.first.isExpired()) {
rep.removeNoLock(rep.first.getKey());
};
The following is multiple choice question (with options) to answer.
A living thing will expire if access to this is removed for a time. | [
"balloons with helium gas",
"their favorite new shoes",
"a comfortable sitting chair",
"ability to experience respiration"
] | D | an animal requires air for survival |
OpenBookQA | OpenBookQA-2214 | quantum-mechanics, quantum-information, superposition
When the compass needle points north, that is like a qubit being in the state $\lvert 0\rangle$, and when the compass needle points east, that is like a qubit being in the state $\lvert 1\rangle$. But a compass needle can also point northeast. The direction northeast is neither north nor east, but it is a superposition of equal parts north and east: if you add a north-pointing vector and an east-pointing vector of equal magnitude, you will get a vector that points northeast. Similarly, the qubit state $\frac{1}{\sqrt{2}}(\lvert 0\rangle + \lvert 1\rangle)$ is neither $\lvert 0\rangle$ nor $\lvert 1\rangle$, but it is a superposition of equal parts $\lvert 0\rangle$ and $\lvert 1\rangle$.
The following is multiple choice question (with options) to answer.
A compass' needle points north the same way that geese know to fly south in winter, because of | [
"unknown circumstances",
"magnetic pants",
"Earth's pull",
"magnetic shoes"
] | C | a compass 's needle lines up with Earth 's magnetic poles |
OpenBookQA | OpenBookQA-2215 | soil, moon
Title: What is the difference between lunar and earth soil I know that the moon has lunar regolith and earth has earth soil, but what is the difference between them? The single biggest difference is the lack of chemical weathering in lunar soils which are subject to physical weathering almost exclusively. If you exclude biological processes, terrestrial rocks undergo significant weathering from water and atmosphere, which the moon lacks.
For example, both earth and moon contain feldspar-rich rocks, however, clays, the result of chemically altered feldspars, are not found on the moon. Neither are oxidized minerals, as the moon has no oxygen-rich atmosphere to speak of.
The following is multiple choice question (with options) to answer.
Which of the following needs soil | [
"a planter",
"a painted house",
"a bamboo stalk",
"an industrial plant"
] | C | a plant requires soil for to grow |
OpenBookQA | OpenBookQA-2216 | thermodynamics
Also, if anyone thinks the scoop is going to explode, please mention that too.
Thanks!
*I don't want to use ice because it will water down the coffee. I don't want to use coffee ice cubes because I'm lazy and also I don't have room in my freezer for an extra tray. I don't want to use metal ice cubes or Coffee Joulies™ or stuff that I have to fish out of my glass because, well just because. I don't want to buy a cold plate like for beer kegs. Let's just go with the premise. TLDR; Get a heavy mug and chill it.
The paraffin in the scoop is functioning as a heat capacitor more than a heat conductor. A solid aluminum scoop of the same dimensions would conduct heat almost as well for large temperature gradients, and better for small temperature gradients (the difference here is whether the temperature gradient can drive significant convective flow). When you first put the scoop in the coffee, the convection will be going like crazy, but my estimation below makes me suspect that the temperature gradient will have become very small before the coffee reaches the desired temperature. It sounds to me like you are looking for a method to reach your desired temperature very quickly, so I will ignore heat exchange with the surroundings, which occurs more slowly.
To simplify the math, lets say you are cooling the coffee from 100 degrees C and the scoop is initially chilled to 0 degrees C. Lets also assume that there is 200 g of coffee, 100 g of aluminum, and 50 g of paraffin (I have the scoop you linked and weighed it). The heat capacity of the paraffin is about 2.5 J/gK, that of the aluminum is about 0.9 J/gK while that of the coffee is about 4.1 J/gK. So without exchanging heat with the surroundings, the system will reach a temperature of about 79 degrees C. That's progress, but it's still pretty hot!
The following is multiple choice question (with options) to answer.
A cup of cold coffee will warm up when heat is applied such as through | [
"a metal chair",
"a flat napkin",
"an electrical plate",
"a wood table"
] | C | a hot plate is a source of heat |
OpenBookQA | OpenBookQA-2217 | 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.
The turtle which lays the most eggs on a beach will | [
"decrease turtle numbers",
"boost hatching numbers",
"stop hatching young",
"eat more sand"
] | B | as the number of eggs laid by an animal increases , the number of eggs that hatch will increase |
OpenBookQA | OpenBookQA-2218 | ## The Attempt at a Solution
I tried to do 1. another way:
The probability that all theses events will occur: 1/4 * 1/3 * 1/2 = 1/24
1-(1/24) = 23/24
Obviously this is wrong. Is the reason it is wrong, because: the complement of "all of these events will occur" is that "not all of these events will occur," meaning, it is not "none of these events will occur."
None of these events will occur is included in the compliment 1-(1/24), but so is that 1 of the events occur, and that 2 of the events occur, etc.
Am I right in my reasoning?
Yes, that's it exactly.
Ray Vickson
Homework Helper
Dearly Missed
## Homework Statement
1.
Suppose that A, B, and C are 3 independent events such that Pr(A)=1/4, Pr(B)=1/3 and Pr(C)=1/2.
a. Determine the probability that none of these events will occur.
Is it just:
(1-P(a))(1-P(b))(1-P(c)) = 3/4 * 2/3 * 1/2 = 1/4
## The Attempt at a Solution
I tried to do 1. another way:
The probability that all theses events will occur: 1/4 * 1/3 * 1/2 = 1/24
1-(1/24) = 23/24
Obviously this is wrong. Is the reason it is wrong, because: the complement of "all of these events will occur" is that "not all of these events will occur," meaning, it is not "none of these events will occur."
None of these events will occur is included in the compliment 1-(1/24), but so is that 1 of the events occur, and that 2 of the events occur, etc.
Am I right in my reasoning?
The following is multiple choice question (with options) to answer.
Which is most likely to occur? | [
"a female fly lays eggs while it is an adult",
"a female fly lays eggs while it is a larvae",
"a male fly lays eggs while it is an adult",
"a male fly lays eggs while it is a larvae"
] | A | a female insect lays eggs during the adult stage of an insect 's life cycle |
OpenBookQA | OpenBookQA-2219 | star, data-analysis, star-cluster, globular-clusters
Title: Dataset containing list of known globular clusters Does anybody know if there is an existing dataset that consists of all known star clusters, their name, and their apparent dimensions or similar? Is it possible to make a query to, or download all SIMBAD objects that are of type "globular cluster"?
Thanks Welcome to astro-informatics!
In SIMBAD with "by identifier", using M13 as a working starting point, you find the type contains "Glc", and there is a Glc catalog number, where the catalog designation is a hyperlink -- this takes you to a page where you can get enough info to track down catalogs in Vizier. In this case, an older catalog VII/44 is listed. It has 137 rows. (There is something like 250 GC for the Milky Way).
Knowing the otype, using SIMBAD under "Criteria query" otype="Glc" returns a count of 22831 globulars, not so great. These include those in other galaxies.
TOPCAT http://www.star.bris.ac.uk/~mbt/topcat/ is about the easiest way to get a workable table.
With TOPCAT knowing the catalog is VII/44 ...
...you can File->Load tables ... under the Vizier button;
in the "Row Selection" frame, check "all rows" and in the "Catalog
Selection" frame choose the "By Keyword" tab. Enter the VII/44 then the "Search Catalog" button. Up pops the catalog; double click the catalog name and you get the catalog downloaded into a sheet-like dialog box.
In general you may get a few things in the Table List frame.
Pick the one with the data. (Some have biblio references etc).
With the table data displayed you can re-order the columns
by dragging them left/right and put the ra/dec into cols 1 and
2 for ds9 for example.
With the proper table chosen in the main Table List frame --
use File -> Save Tables(s)/Session and save the data.
The "Output Format" has CSV -- good enough.
The little icon looks like 4 stacked coins (database) will let
you export directly to a PostgreSQL database! that is a different
The following is multiple choice question (with options) to answer.
Which list contains all satellites? | [
"a plane and a helicopter",
"Venus and the Kuiper belt",
"space shuttles and rocket launch platforms",
"the ISS, the moon, Europa"
] | D | a satellite orbits a planet |
OpenBookQA | OpenBookQA-2220 | zoology, ecology, diet, predation
Cheetahs have been reported to suffer from intraguild competition by lions Panthera leo, spotted hyenas Crocuta crocuta and occasionally leopards Panthera pardus. These larger predators represent a threat to the smaller-bodied cheetahs as they can affect their food intake by limiting access to high resource areas or kleptoparasitism (e.g. 10–12% of kills are kleptoparasitized in Serengeti National Park (SNP)), and reduce population sizes via increased cub mortality (e.g. 73% of cub mortality was due to predation in the SNP). In response, cheetahs often demonstrate avoidance behavior to minimize interactions with dominant carnivores , with spatial and temporal partitioning regarded as the principal behavioral mechanisms by which this is achieved. Accordingly, cheetahs have been described as a refugial species that seeks competition refuges within the landscape with low densities of lions and spotted hyenas.
Rostro-García S, Kamler JF, Hunter LT. To kill, stay or flee: the effects of lions and landscape factors on habitat and kill site selection of cheetahs in South Africa. PLoS One. 2015;10(2):e0117743. Published 2015 Feb 18. doi:10.1371/journal.pone.0117743
(removed the citations)
The definition of the terms used in the above citation:
Intraguild predation, or IGP, is the killing and sometimes eating of a potential competitor of a different species. This interaction represents a combination of predation and competition, because both species rely on the same prey resources and also benefit from preying upon one another. - Wikipedia
Kleptoparasitism, literally meaning parasitism by theft, is a form of resource acquisition where one animal takes resources from another. Although kleptoparasitism of food (i.e., kleptoparasitic foraging) is the best known example, the stolen resources may be food or another resource such as nesting materials. - Sciencedirect.com
The following is multiple choice question (with options) to answer.
A person who hunts lions down for trophy prizes contributes to their species' | [
"growth",
"encouragement",
"consideration",
"ruination"
] | D | harming an animal species causes that animal 's population to decrease |
OpenBookQA | OpenBookQA-2221 | python, python-3.x, game
continue
player.gold -= choice.value
player.inventory.append(choice)
print(f'--- You bought a {choice} for {choice.value} gold.')
class Slime(Character):
The following is multiple choice question (with options) to answer.
A person wants to collect green slime, so they seek out | [
"damp gutters",
"neat pictures",
"old dogs",
"dry bones"
] | A | algae is found in bodies of water |
OpenBookQA | OpenBookQA-2222 | the-sun, earth
Title: If the Sun got larger, but maintained its luminosity, would the Earth get hotter or colder? A recent question If the Sun were bigger but colder, Earth would be hotter or colder? asked - if the Sun got bigger and cooler, would the Earth heat up or cool down. I think the answer to that is mainly that it depends on the final luminosity.
However, what I want to know here (hypothetically), is if the Sun got larger and it's effective temperature decreased such that it's luminosity was unchanged; how would that affect the equilibrium temperature of the Earth? I suspect the answer may involve the wavelength dependence of the albedo, emissivity and atmospheric absorption of the Earth.
Another, less hypothetical, way of asking this is, if you put an Earth-like planet at different distances from stars with a variety of temperatures, such that the total flux incident at the top of the atmosphere was identical, how would the temperatures of those planets compare? The key issue is the opacity of the atmosphere, because I presume the question is about the temperature at the solid surface of the Earth. The atmospheric opacity can be seen from https://physics.stackexchange.com/questions/135260/can-someone-explain-to-me-the-concept-of-atmosphere-opacity, where you can see that the "rainbow" of maximum heat flux from the Sun happens to hit a kind of hole in atmospheric opacity. That has a significant warming effect on the Earth, and is exacerbated by the Greenhouse effect. If sunlight was further into the infrared, the graph shows that much more of it would be intercepted in the atmosphere. That would make the surface significantly colder, though certainly not a factor of 2 colder.
No doubt the question is of more than passing interest, because M dwarfs are the most numerous main-sequence stars and are therefore interesting for life. To have life near an M dwarf, the planet would need to be closer than Earth is to the Sun, but the effect of moving the planet closer and shrinking and cooling the star would be similar to leaving Earth where it is and making the star cooler and larger. So the nature of atmospheric opacity for wet atmospheres must be of great significance for understanding the prospects for life around M dwarfs.
The following is multiple choice question (with options) to answer.
Earth is warmed mostly by a large yellow dwarf star that is | [
"hollow",
"local",
"furthest",
"dark"
] | B | the Sun is the star that is closest to Earth |
OpenBookQA | OpenBookQA-2223 | reference-request, machine-learning, combinatorics, optimization, search-problem
Reproduction and Mutation
Once you have selected your survivors of one round, you have to create the next generation from them (do the parents survive and are part of the next generation?). There are two major strategies: mutation and recombination.
Mutation is quite clear, although the specifics can differ. For every position in an individual's sequence, mutate it with some probability. You can do this independently for every position, or choose the number of mutations randomly, or you can perform different mutations with different probabilities (such as inserting a new element, removing one, changing one, ...). Mutation is usually about small changes.
Recombination, that is combining aspects of two or more solutions to a new one, is more tricky but can allow big steps, that is leaving one "fitness mountain" and move directly to the slope of another (which may be higher). A classic idea is the crossover; I don't know whether that makes sense here (it seems to me that swapping the prefix of a given sequence for something else will most likely devalue the suffix). Maybe you can use knowledge about the level and positions of the game character at different points in the sequence to guide this, that is create crossover points only where the character is at the same position in both sequences.
Termination
When do you stop? After $N$ generations? When the maximum fitness has not improved since $k$ rounds? Do you stop early if some fitness (with above function, $1$) has not been reached after $n$ rounds in order to eliminate useless initial populations early?
The following is multiple choice question (with options) to answer.
A way to reproduce is to | [
"plant dishes",
"produce ovum",
"make money",
"litter carpet"
] | B | An example of reproduction is laying eggs |
OpenBookQA | OpenBookQA-2224 | theoretical-biology, hematology, red-blood-cell
**As an intern, I once had the very sorrowful experience of admitting an healthy appearing, exuberant 4 year old child to the pediatric surgical service. The only presenting symptom was that the child started squatting during exertion (not good), and on exam, had a murmur which was caused by aortic stenosis. This was long before imaging studies were as sophisticated as they are now. The pediatric cardiac surgeon took him to the operating room (OR) to replace the valve, but there was so much atherosclerotic aortic damage that there was no healthy tissue which could hold sutures in place. The child died in the OR. I don't know what would have been done today, but had the child stayed home, they might have had a couple more years with the parents, who hoped for an uneventful procedure. So the exercise involved in this answer was fun, but the memory it brought back is still quite sad.
The following is multiple choice question (with options) to answer.
What might have a negative impact on a child | [
"buying them things",
"hitting them",
"loving them",
"hugging them"
] | B | harming something has a negative impact on that something |
OpenBookQA | OpenBookQA-2225 | metal, toxicity, radioactivity
239Pu's radioactivity is in the form of alpha particles, which are only dangerous if emitted internally, because they can't penetrate the epidermis. The hazard then seems to me like it would depend crucially on how the internal exposure occurred. If you eat an alpha emitter, then it will stay in your body until it's either excreted or decays. The half-life for excretion of organic or metallic Hg is on the order of months, so that's probably a reasonable order-of-magnitude estimate for other heavy metals. On the other hand, there are people at nuclear weapons labs who do machining of plutonium pieces, and this kicks up plutonium dust. They do this machining inside glove boxes, and I assume the chips and dust are swept up very carefully. The dust can be breathed in, and microgram particles that get into your lungs are likely to remain there for the rest of your life (Lenntech, ATSDR 2010). From the lungs, it can also migrate to the bones or liver. ("Much less than 1%" of ingested Pu would do so.)
The following is multiple choice question (with options) to answer.
When the body needs to rid itself of potentially toxic elements within it, what process is utilized? | [
"process of purging",
"process of circulation",
"process of respiration",
"process of cooking"
] | A | the excretory system removes waste from the body |
OpenBookQA | OpenBookQA-2226 | thermodynamics
Say you own a theme park where, every hour, each adult has to pay ${\rm d}\mu_a=\$7$ (money=energy) and each kid has to pay ${\rm d}\mu_k=\$3$.
We assign positive signs to when they put money out of their pockets.
If there are $n_a=10$ adults and $n_k=5$ kids in the park, and if this number of people stays fixed (${\rm d}n_\text{totoal}=0$ over some time), then they together have to spend
$$n_a\cdot {\rm d}\mu_a + n_k\cdot {\rm d}\mu_k = \$70 + \$15 = \$85$$
Now say you, the park owner, are not allowed to actually make any money (${\rm d}G=0$) and you relax the condition that the kids have to pay any money at all. That is, now just the adult have to pay ... and since the money has to go somewhere, the kids are on the receiving end. Then the ten parents still spend $\$70$ per hour and now the five kids will split that money among each other. Each kids receives
$$-{\rm d}\mu_k = \frac{1}{n_k}\cdot n_a\cdot {\rm d}\mu_a = \frac{1}{5}\cdot \$70 = \$14$$
The comparison with "money per time" lacks in that here people don't bring in money just from coming to the park (as it's the case with particles coming into the system and energy). But I hope this clear up the meaning of factor $\frac{1}{n_k}$ clear.
The following is multiple choice question (with options) to answer.
Energy will be expended for | [
"a monkey with a puncture wound to get better",
"pencils to lay flat on a desk",
"paper to flutter around",
"a flower to lay dormant"
] | A | an organism requires energy for repair |
OpenBookQA | OpenBookQA-2227 | Shanonhaliwell April 8th, 2018 03:31 PM
Quote:
Originally Posted by romsek (Post 591335) outstanding, you seem to be getting the hang of things.
Thanks to you, I was able to do it.
All times are GMT -8. The time now is 12:30 AM.
The following is multiple choice question (with options) to answer.
Every 1440 minutes | [
"the moon is full",
"there's a lunar eclipse",
"a new year starts",
"the sun sets in the west"
] | D | the sun setting occurs once per day |
OpenBookQA | OpenBookQA-2228 | zoology, species-identification, ornithology, behaviour
Title: What is this crow eating, and is it a common part of the corvid diet? Here's a picture (by Rob Curtis) of a crow carrying and eating the corpse of what looks a bit like a small hawk or falcon:
Other pictures clearly show the crow is eating the dead bird. This image shows the underside of the head and beak; this one shows its legs, which are grayish.
What bird is being eaten?
Is this bird a usual part of the corvid diet? Or did the crow just opportunistically scavenge a dead bird? Crows are omnivorous, and will eat almost anything they find or can kill.
In this case the prey looks like a Yellow-Shafted Flicker.
The following is multiple choice question (with options) to answer.
Which animal is most likely to eat another living animal? | [
"deer",
"elephant",
"worm",
"lion"
] | D | In the food chain process an animal has the role of consumer which eats other animals for food |
OpenBookQA | OpenBookQA-2229 | 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.
A person yells inside a garage. Their voice echoes and they hear | [
"a bird chirping away",
"a dog barking loudly",
"a car engine rev",
"a shout repeating softer"
] | D | when a sound is produced inside of a room , there is sometimes an echo after the sound |
OpenBookQA | OpenBookQA-2230 | 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.
Which is a visible example of water vapor | [
"aerial clouds",
"snow",
"cigarette clouds",
"ice"
] | A | water vapor is found in the atmosphere |
OpenBookQA | OpenBookQA-2231 | fluid-dynamics
Title: Feeling the Breeze This question is based on an odd phenomenon I noticed last week. Since then, I've been collecting more data to try to get an accurate picture of the facts.
Each morning, I go to my bus stop. It's on a main road, and when I get there, there is a lot of traffic. Every couple minutes a large truck goes by, and I suddenly feel a breeze go by me. The catch here is that there is about a one-second delay between the truck passing by and the start of the breeze. What is causing this phenomenon?
Here's some more information: I'm about three meters from the road; The breeze begins roughly one second after the truck passes by, and last for one and a half seconds; The breeze seems to be blowing diagonally, from my rear left to my front right side (I'm in America, so the trucks go from left to right); The breeze does not seem to depend on truck size (although small vehicles do not cause it).
I do have two possible explanations for the breeze:
1) The truck goes by at about 30 mph. This could create a tiny, short-lived vacuum at the back as it moves forward, thereby drawing air towards the rear of the truck.
2) The breeze is the result of some sort of "bow shock" from the truck.
Neither of these explanations seem to satisfy me, though, because they seem a bit far-fetched, and I am certainly no expert in fluid mechanics. What could be the cause of the breeze?
As a last note, I have no idea what tags to use for this question, because I don't know what the cause of the breeze is. Suggestions for these and other edits are welcome. What you're feeling there is the wake behind truck. As the truck passes through the air, it imparts momentum and generates quite a lot of turbulence (allowing it to impart even more momentum). It takes a little bit of time for that momentum to spread outward and reach you. As that air is 'pulled' behind the truck more will be drawn in from the sides. These two effects give the flow that left/forward direction that you feel.
The folks at Cornell have some nice animations and pictures of vehicle wakes.
The following is multiple choice question (with options) to answer.
Wind blowing southwest at high speeds can, when interacting with a car moving southwest at high speeds, | [
"break the car's speed",
"stall the car's speed",
"slow the car's speed",
"heighten the car's speed"
] | D | a force continually acting on an object in the same direction that the object is moving can cause that object 's speed to increase in a forward motion |
OpenBookQA | OpenBookQA-2232 | 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 has a respiratory system then they are able to remove from a room | [
"time of day",
"all warmth",
"the paint color",
"breathable gas"
] | D | the respiratory system takes in oxygen from the air |
OpenBookQA | OpenBookQA-2233 | evolution, zoology
Let's say the environmental challenge for two different kinds of carnivore (let's call them Bogs and Dats) is to catch Mophers. Both Bogs and Dats initially have the same medium-to-short muzzles. Some Bog individuals figure out that they can dig Mophers out of their burrows, and some Dat individuals figure out that they can catch Mophers at night when the Mophers leave their burrows. Both strategies are successful. Some Bogs happen to have longer muzzles than their cousins, and find it turns out that longer muzzles work synergistically with the digging strategy, allowing Bogs to stick their noses into the Mopher burrows to grab escaping Mophers. The resulting fitness advantage results in an increase of the long-muzzle trait in further generations of Bogs. Note that in this scenario it is the adaptive behavioral strategy that creates selective pressure that favors a particular genetic adaptation.
Dats on the other hand, because of their nocturnal hunting strategy, benefit from improved night vision; and long muzzles don't provide any fitness advantage to Dats because Dats don't dig Mophers from their burrows. As long as Bogs and Dats don't hybridize, they will most likely end up with long and short muzzles respectively.
The Waddington effect, also called “Genetic Assimilation”, is somewhat more direct:
An environmental stress causes a proportion of a population to develop one or more abnormal traits, by interfering with embryological development.
If there is a selective pressure in the environment that favors some subset of those traits, individuals whose genetic makeup makes them more likely to develop that subset of traits, those individuals are likely to produce more descendants than other members of the population.
If being “more likely to develop” that subset of traits results from a weakening of genetically determined development controls that would otherwise prevent development of that subset of traits, then the subset of traits can eventually become the normal phenotype.
The following is multiple choice question (with options) to answer.
The more hawks that chow down on voles, the | [
"the happier voles in an area",
"the bigger voles in the area",
"fewer voles in that area",
"more voles in the area"
] | C | if a new predator begins eating prey then the population of that prey will decrease |
OpenBookQA | OpenBookQA-2234 | everyday-life
Title: Strange pattern on car windows
A couple of days ago I was in a friend's car, and I noticed this pattern on the windows; I took a picture of the sun through the window to make it clearly visible.
The night before had been quite cold, but I don't think that the temperature went below $0$ °C, even though I am sure that it did some days before.
I can speculate that the phenomenon originated from some condensation/freezing of humidity on the outside of the car window, so I searched the web for pictures of water condensation and frost patterns (and also water staining) on car windows, but couldn't find anything similar.
What could be the origin of this intricate pattern? From your question, I can guess that the weather is rainy in your region.
When you drive a car in the rain, the water drops pass your windows at an angle. This, plus wind and other winter stuff causes the path of the drops to twist and jiggle like in this photo
I would also guess that the rain stopped while still driving, so the water could've evaporated in this pattern. The sunlight then makes those residues more pronounced when you took the picture.
Take a look at the following picture from a google search of 'water stains on glass'. To me it looks similar to your photo, just without the effect of moving window (keep in mind that the residues in the water may differ from one place to another due to pollution and etc., so the stains don't have to look the same).
The following is multiple choice question (with options) to answer.
Cars driving over a stone road throughout a year, including hot days and cool nights, may cause the road to | [
"evaporate",
"burn",
"flood",
"break up"
] | D | mechanical weathering is when rocks are broken down by mechanical means |
OpenBookQA | OpenBookQA-2235 | human-biology
Title: Why do we sweat after drinking water and running? Why do we sweat after running?
Also we sweat sometime after drinking lots of water. Why it is so?
Can someone please enlighten me in this regard? Exercise, such as running, increases muscle activity. This increases the energy demand of these tissues, which increases the rate of cellular respiration. Respiration releases heat as a by-product, therefore the body is hotter during and after exercise.
Sweating is a homoeostatic mechanism to keep core body temperature constant. It is a response to lower the body temperature. When the body becomes too hot, sweat is released onto the surface of the skin. The water from the sweat then takes some of the excess heat energy from the body and uses it to evaporate. Because water has a relatively large specific heat capacity a lot of heat can be carried away by this method.
The following is multiple choice question (with options) to answer.
Sweat is produced | [
"when sleeping peacefully at night",
"when on a long jog in sweltering weather",
"when sitting in a recliner in an air conditioned house",
"when sitting on the front porch on a breezy day"
] | B | when the body is hot , sweat is produced to cool the body |
OpenBookQA | OpenBookQA-2236 | species-identification, marine-biology
Title: help identify this fish
I came across this washed up fish in Panama City, Florida in November 2015. I'm guessing it's a puffer fish but I can't find anything like it online.
Thanks. This is a kind of trunkfish. (They have different names, this could be a smooth or spotted trunkfish.). It's really a lovely and comical little fish when observed alive in coral reefs. It has the ability to change its coloration depending on whether it's excited or calm, or to minimize its contrast to the background. It is related to puffer fish.
It has a boxy, triangular body shape, and propels itself with relatively tiny, delicate fins. Like pufferfish, they are toxin producers.
In death, the body shape and coloration are different, of course. Never saw a dead one before; sad. The juveniles are adorable:
Members of this family occur in a variety of different colors, and are notable for the hexagonal or "honeycomb" patterns on their skin. - Wikipedia
The following is multiple choice question (with options) to answer.
A creature's habitat, if it has flippers and carries a home with it, is likely | [
"mountainous",
"arid",
"salty",
"dry"
] | C | a sea turtle lives in the ocean |
OpenBookQA | OpenBookQA-2237 | 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 lot more sunlight is getting through to the forest floor in the summer than the summer before. | [
"a lumber company got resources from the forest",
"the sun is a lot brighter than the year before",
"A piece of the sun has been placed on the forest floor",
"mirrors have been placed in the tree tops by squirrels"
] | A | cutting down trees in a forest causes the number of trees to decrease in that forest |
OpenBookQA | OpenBookQA-2238 | electrical-engineering, ethics, sales, safety
But all of those steps are going way above and beyond what you're obligated to do in this particular case. This is especially so when there is a safe usage for the product along with an unsafe approach. And any of those actions are likely to irreparably damage your relationship with that client. Damaging the relationship will impair your credibility with them and make it less likely that they'll listen to your concerns.
So your obligation is to lay it out to them in unambiguous terms that you believe they need to stop using the product in their "preferred" manner and that your firm will no longer provide any support whatsoever regarding future use of that product in that configuration.
The following is multiple choice question (with options) to answer.
A person may bring harm to the environment by | [
"burning shoes",
"recycling",
"filtering water",
"burning sticks"
] | A | humans discarding waste in an environment causes harm to that environment |
OpenBookQA | OpenBookQA-2239 | charge, electric-current, flow
http://amasci.com/miscon/eleca.html#cflow
Energy, however, is not transmitted by one electron moving all the way around the circuit to the load, but rather through waves in the electrons and more importantly, the associated electric field. It's the same way that mechanical energy is transmitted in, say, a pole that is pushed from one end. The pole compresses slightly, and a sound wave thus appears, initially containing all the energy within your "push", and then travels down it, progressively distributing that energy amongst all the atoms within the pole until they are all moving in a single direction (here I imagine the pole pushed in a vacuum, as in interstellar space, with no other forces acting). The same goes with electrons in the circuit - though I should point out the following model is a bit simplistic but is more to convey the point of how the energy is transmitted than to detail the actual behavior of the electrons, which involves quantum mechanics and is subject to many of the same caveats as one sees within in an individual atom or molecule. But in this loose sense, when you throw the switch, now an electromagnetic wave travels down, setting the electrons ahead in motion and thus distributing its energy throughout the circuit. Of course, the core atoms of the metal are relatively fixed despite the electron motion, so the latter will tend to lose that energy to collision with them, unlike the pole where everyone, atoms and electrons together, start going in synchrony, and thus you have to keep supplying energy to them with a power source like a battery or generator which effectively keeps "pushing the pole" and thus keeps energy going into it - now think about a pole that is now not in vacuum but in molasses, and you have to keep pushing it to keep it moving. This pushing on atoms, of course, is how electrical devices can use electrically transmitted energy to do useful tasks.
Electromagnetic waves, and sound waves, thus energy, travel much faster than the electrons and the atoms in both the circuit and pushed pole. Energy is what lights up your light bulbs, and energy is what makes your computer operate. Since energy travels fast, these devices start operating "at the flick of a switch".
The following is multiple choice question (with options) to answer.
A person can charge something which passes energy through it by | [
"reaching forward",
"looking at it",
"swiping left",
"hooking it up"
] | D | when an electrical conductor is plugged into an outlet , a circuit is completed |
OpenBookQA | OpenBookQA-2240 | Kudos [?]: 4 [2] , given: 0
Re: Good set of PS 2 [#permalink] 19 Oct 2009, 08:02
2
KUDOS
Bunuel wrote:
4. A contractor estimated that his 10-man crew could complete the construction in 110 days if there was no rain. (Assume the crew does not work on any rainy day and rain is the only factor that can deter the crew from working). However, on the 61-st day, after 5 days of rain, he hired 6 more people and finished the project early. If the job was done in 100 days, how many days after day 60 had rain?
(A) 4
(B) 5
(C) 6
(D) 7
(E) 8
This one was solved incorrectly:
Days to finish the job for 10 people 110 days.
On the 61-st day, after 5 days of rain --> 5 days was rain, 55 days they worked, thus completed 1/2 of the job, 1/2 is left (55 days of work for 10 people).
Then 6 more people was hired --> speed of construction increased by 1.6, days needed to finish 55/1.6=34.375, BUT after they were hired job was done in 100-60=40 days --> so 5 days rained. They needed MORE than 34 days to finish the job, so if it rained for 6 days they wouldn't be able to finish the job in 100(40) days.
I solved in a more easier way I think:
1) 10 man 110 days --> need for 1100 man.days
2) 55 days with 10 men --> 550 man.days
3) 40 days with 16 men --> 640 man.days
--> total man.days equals 1190 vs need for 1100 --> days of rain equals 90/16 max --> 5.625 --> rounded to 5
Senior Manager
Joined: 31 Aug 2009
Posts: 420
Location: Sydney, Australia
Followers: 6
Kudos [?]: 165 [1] , given: 20
The following is multiple choice question (with options) to answer.
When rain falls for two solid weeks, flooding will be evident | [
"at the middle of a mountain",
"inside of the mountain",
"at the base of a mountain",
"at the top of a mountain"
] | C | as elevation of a place decreases , how much a flood will affect that place will increases |
OpenBookQA | OpenBookQA-2241 | meteor
Title: Trying to identify something I saw in the sky I'm trying to identify something I saw in the sky. This occurred in central Virginia (Louisa county), US on Sunday at around 2:15 AM EST. It started as a ring of what looked like smoke, high in the sky. The ring got gradually larger. Then a small light moved out of it. The light looked like a star but it was moving about the 'relative' speed of an airplane viewed from the ground. I say relative because I think this was higher up than an airplane and so it was probably moving faster. The light had a puff behind it which was much larger than the light (so it was much bigger than the entrails of a jet plane). When I say 'big' or 'small' I mean it relative to the view of someone standing on the ground. I kept observing this light moving across the sky until I lost it in the trees.
I have not seen anything like this before. If I had to guess, I'd say it was possibly a military plane at high altitude moving at high speed. I guess it could also be a meteor that caused the ring when it hit the atmosphere and moved off at a strange angle. However, I have never seen a meteor move that slow. They usually zip fast across the sky. Maybe it's a meteor that hit the atmosphere at an angle that slowed it down? Anyone know what it could have been?
Edit: I saw this photo submitted to the american meteorologic society. It's about the same time and looks exactly like what I saw. It was from someone in PA at 2:30am.
The following is multiple choice question (with options) to answer.
A shout is made into the night sky and carries | [
"a paper bag",
"a baby",
"a stick",
"on the gales"
] | D | air is a vehicle for sound |
OpenBookQA | OpenBookQA-2242 | metabolism, nutrition, digestive-system
Title: Do I have to chew for digestion to kick in? Liquid nutrient-rich products (such as Soylent) are consumed without chewing. But if I have to chew to initiate digestion, are those nutrients really "processed"? If you had to chew to digest, then beverages like sugary sodas would never be digested or provide calories or nutrients, as you (generally) don't chew when you drink them. No, chewing is not required for digestion or nutrient absorption. Chewing is important when eating solid foods, as the chewing action breaks down and begins to solublize the food, and stimulates the production of saliva, which contains enzymes that begin to break down the food prior to digestion in the stomach and intestines.
The following is multiple choice question (with options) to answer.
Which is likely to be digested? | [
"metal",
"water",
"hush puppies",
"pain"
] | C | digestion is when stomach acid breaks down food |
OpenBookQA | OpenBookQA-2243 | star, night-sky
Title: What is this rapidly twinkling red, blue, and white star I saw? Last night, I was on my balcony at 1AM (PST) and I looked up and saw two stars near the horizon (I'd guess ~30 degrees above the horizon), and they were "twinkling" about twice as fast as other stars higher in the sky, and I could clearly see them changing from red to white to blue repeatedly. Other stars in the sky only appeared white to me, and didn't seem to "twinkle" as rapidly as these two stars did. The red and blue make me think of red-shift and blue-shift, but I don't know how I would see both from the same object.
What was I seeing?
I don't know if it helps, but I am in the Los Angeles area, and I was looking in a roughly north direction. almost exactly to the east, according to google maps.
Edit: I tried taking a picture, but light pollution from the nearby street lights wouldn't permit me taking a decent picture. However, I noticed a group of three stars close together in nearly a perfect almost vertical line, and managed to find that in Stellarium. I think I found the two stars I am seeing: Procyon and Sirius
Is there anything about either of these stars that would make them show as red/blue? It's most probably Sirius. At this time of year (at 1 am local time) it's low in the sky in the East, so there is a lot of atmosphere in the way, and as Sirius is a bright bluish star, it will show all the colours described as it twinkles.
The following is multiple choice question (with options) to answer.
The stars at night, though bright and glowing merrily, are | [
"distant",
"close",
"touchable",
"near"
] | A | the stars in the night sky are very far away from the Earth |
OpenBookQA | OpenBookQA-2244 | material-science
Title: Optimal material for a hammer head I was watching a TV show in which a gold hammer was mentioned. It was not serious but caused me to wonder whether gold would be a good material and, if not, what else might be. An attraction of gold is that it has a high density but that advantage is probably negated by being more malleable than steel. So, I started to wonder what properties I need to consider. Some materials may be hard but liable to shatter on impact.
Let's suppose that the dimensions of the hammer are fixed: a fixed handle and a fixed size and shape for the head. The objective is to drive steel nails into a variety of hard substances.
Cost is not a factor, nor ease of construction, nor safety. It will need to last long enough to be used so francium and various heavy elements are not suitable. If depleted uranium is a good material then this would be acceptable. It is used for armour piercing shells presumably because of its density but there are denser materials. Is it that it is cheaper than gold or osmium?
What properties should I be researching?
Additional: to make the question more manageable, I will require a homogenous pure material for the head not an alloy. I hope that this makes me more a question of physics rather than engineering. This is a thought experiment rather than a real project. What the optimal hammer head material is depends on what we are optimizing for.
A standard hammer has a hard head that has high density, held by a strong but usually light handle. If it has length $l$ and is accelerated at some acceleration $a$ set by user muscle strength it will reach a velocity $v$ after having traversed a distance $\sim l$; that is, $l=at^2/2$ gives $t=\sqrt{2l/a}$ and $v=\sqrt{2la}$. The kinetic energy will be $K_e\approx mla$. So a long and heavy hammer will be able to drive a nail more deeply (to a depth $K_e/F$ where $F$ is the resisting force). So more mass and length seems good... but obviously not too much either.
The following is multiple choice question (with options) to answer.
Which material is most likely to be considered hard, in the field of geology? | [
"plastic jewels",
"cheese",
"real jewels",
"chalk"
] | C | measuring the hardness of minerals requires scratching those materials |
OpenBookQA | OpenBookQA-2245 | food, nutrition, energy-metabolism
Title: What are the bare minimum nutrients required to survive as a human? I am trying to determine the bare minimum nutritional requirements to survive as a human, ignoring energy (caloric) requirements. Another way to ask this question is: What elements can humans not live without? I am not inquiring solely about what nutrients are needed, but also their approximate amounts.
Imagine pills that a person can take that covers all their base nutritional needs and that after taking this pill the person can eat whatever they want to meet their caloric requirements. Hypothetically, this pill could have some amount (how much?) fat, carbohydrates, protein, fiber, minerals, and vitamins, and the person could subsequently eat any other food to meet their caloric requirements knowing their nutritional needs would already be otherwise met. Lets ignore the possibility of the person suffering from health issues due to eating too much of any specific food to meet their caloric requirements (e.g., taking the magic pills and then eating only butter).
A person in this situation could think "Ok I've got most of my bases covered, now I just need to ingest another 1000 calories of (almost) anything I want).
What nutrients are absolutely necessary for humans to survive indefinitely, and how much of these nutrients are required?
I am hoping for a complete list with approximate amounts (e.g., 20g fat, 20g carbohydrates, 1mg Vitamin X, .05mg Vitamin Y, 10mg mineral X). Essential nutrients include (NutrientsReview):
Water
9 amino acids: histidine, isoleucine, leucine, lysine, methionine,
phenylalanine, tryptophan, threonine, valine
2 fatty acids (alpha linolenic and linoleic acid)
Vitamins: A, B1, B2, B3, B5, B6, folic acid, biotin, B12, C,
D, E and K (and choline, which is considered a vitamin-like substance)
Minerals: calcium, chromium, chloride, copper, iodine, iron,
manganese, molybdenum, phosphorus, potassium, selenium, sodium, zinc
The following is multiple choice question (with options) to answer.
What would provide the most nutrients? | [
"a used popcorn bucket",
"an empty can of corn",
"a dead strawberry bush",
"a pickled jicama root"
] | D | nutrients are a source of energy for living things |
OpenBookQA | OpenBookQA-2246 | evolution, ornithology, ethology, sexual-selection
Bateson P. 1978. Sexual imprinting and optimal outbreeding. Nature 273, 659 - 660.
Bereczkei T, Gyuris P, Weisfeld GE. 2004. Sexual imprinting in human mate choice. Proceedings of the Royal Society of London, Series B: Biological Sciences 271: 1129–1134.
Immelmann K. 1972. Sexual and Other Long-Term Aspects of Imprinting in Birds and Other Species. In Advances in the Study of Behavior, Vol. Volume 4 of, pp. 147–174, Academic Press
The following is multiple choice question (with options) to answer.
Two rabbits frequently copulate. The result for the rabbits will likely be | [
"broods",
"snacks",
"teeth",
"burrows"
] | A | reproduction produces offspring |
OpenBookQA | OpenBookQA-2247 | optics, geometric-optics
EDIT:::Clarifications
This question is the result of a debate with my friend, who says the room would be dark and me who says otherwise.
Now being said that let's move to specifics...let's assume that the room is a cuboid and the light source is say a light bulb i.e. an isotropic source like a typical room at ceiling. and the observer with infinitesimally small view port looking from one of the wall presumably neither the ceiling nor floor.
I hope this suffices. You use the verb "to be," which is rather deceptive in this situation (and in questions of optics generally). The room itself would not "be dark" or "be light," it would be a collection of various particles, some of which would be photons in the visible spectrum. It really only makes sense to ask how the room would appear to an observer looking through the viewport.
Even if you had completely reflective surfaces, the way the room appeared would depend significantly on the orentientation of the mirrors, the orientation of the viewing hole, the focus of the light, and perhaps most importantly, the refractive and diffusive properties of the mirrors. Ultimately, the appearance of the room would be a result of the light that falls upon the viewport. While there are an infinite variety of possible arrangements, the two extremes roughly align with the two possibilities you suggest.
For the room to look completely dark, no light paths fall on the viewport. A laser perpendicular to two parallel mirrors with the line of sight also parallel to the mirrors would produce this effect.
For the room to look completely bright, all (or however much you require to meet that definition) light paths fall on the viewport. A room in the shape of a truncated paraboloid with the viewport at the focal point would produce this effect.
Edit
I decided to move these up to my answer to avoid a prolonged comment conversation.
The following is multiple choice question (with options) to answer.
A person wants a room that is artificially brightened to go back to darkness, so they | [
"pull a cart",
"dump a can",
"flick a window",
"adjust a switch"
] | D | a switch is used to stop the flow of current in an electrical circuit |
OpenBookQA | OpenBookQA-2248 | javascript, algorithm, machine-learning
Title: Reinforcement Learning for Flappy Bird in JavaScript To give a bit of a background, I'm organizing a small session about reinforcement-learning, specifically Q-learning, to a group of high school students in the following month to give them a glance into the kind of opportunities waiting for them to tackle in this amazing field of AI and Computer Science. Just a small stint to motivate them, to be honest :)
I hence seek the guidance of this wonderful community (that is you!) to judge the understandability and the readability of my code which I had drafted some time ago. The code which follows is predominantly written in basic JavaScript and since it's targeted for a set of audience who aren't completely comfortable with most of the modern paradigms, I would like to keep it as simple as possible. I've tried to document the code heavily covering potentially all important cases in layman terms to make it more clear. You can see the effect of the code in action here: https://nileshsah.github.io/reinforcement-learning-flappybird/ (you just need to tap the game to start and then leave it alone for the computer shall learn to play it by its own). The complete repository for the game and the algorithm can be found here.
I do realize that it's a bit too much of a code to review (around 300 lines) but if in the process you get to learn something new then oh well, I guess it'll be a win-win situation for both of us :) Please take your time and share your thoughts regarding "which part of the code is hard to comprehend and how I can improve it".
Sharing the code: https://github.com/nileshsah/reinforcement-learning-flappybird/blob/master/js/brain.js
/**
* The file contains solely the Q-learning model for training our flappy bird.
* It takes input from the environment such as the position of the flappy bird,
* the tubes etc and responds back with the appropriate action to take.
*
* Author @nellex
*/
The following is multiple choice question (with options) to answer.
Which of the following is a learned behavior? | [
"thinking",
"cooking",
"hearing",
"breathing"
] | B | animals learn some behaviors from watching their parents |
OpenBookQA | OpenBookQA-2249 | ecology, population-dynamics, ecosystem, antipredator-adaptation, predation
I would also like to talk about other things that might be of interest in your model (two of them need you to allow evolutionary processes in your model):
1) lineage selection: predators that eat too much end up disappearing because they caused their preys to get extinct. This hypothesis has nothing to do with some kind of auto-regulation for the good of species. Of course you'd need several species of predators and preys in your model. This kind of hypothesis are usually considered as very unlikely to have any explanatory power.
2) Life-dinner principle. While the wolf runs for its dinner, the rabbit runs for its life. Therefore, there is higher selection pressure on the rabbits which yield the rabbits to run in average slightly faster than wolves. This evolutionary process protects the rabbits from extinction.
3) You may consider..
more than one species of preys or predators
environmental heterogeneity
partial overlapping of distribution ranges between predators and preys
When one species is absent, the model behave just like an exponential model. You might want to make a model of logistic growth for each species by including $K_x$ and $K_y$ the carrying capacity for each species.
Adding a predator (or parasite) to the predator species of interest
... and you might get very different results.
The following is multiple choice question (with options) to answer.
An omnivore, such as a bear, will have many animals that are | [
"cuddling with it",
"hungry for it",
"consuming it",
"fearful of it"
] | D | omnivores are predators |
OpenBookQA | OpenBookQA-2250 | bacteriology, food, hematology, toxicology, parasitology
Title: Blood consumption Is consumption of blood more "dangerous" compared to meat?
There was a news-article about unnatural chemicals found in the blood of mothers. This reminded me about a question I have pondered upon from time to time. Now, I am not a vampire, but curious as to the nature of blood vs meat in animals. More specifically unhealthy components.
There are various examples of viruses being in danger of spreading by consumption of raw blood like ebola, H5N1 etc. (But then also meat etc.)
Perhaps easier if I throw out some questions to show what I am asking:
Are there more of such in blood then meat?
Are there other things that can be worse in blood even after preparing? Like cooking, conservation etc.
Are parasites etc. more frequently found in blood?
Are there organisms that are highly resilient to heat treatment found in blood?
Are there more heavy metals in blood then meat? (Which I assume cooking does not give much of a difference.)
Other toxins?
Some references:
http://www.eufic.org/article/en/food-safety-quality/animal-health/expid/review-animal-diseases/
http://www.fao.org/avianflu/en/qanda.html
Is consumption of blood more "dangerous" compared to meat?
Actually yes, a simple high dose of blood is enough to kill. The cause is, though it is most important thing to live when flowing the vessel, it's highly toxic when consumed. There are high chances of getting haemochromatosis or Iron overload.
Source and More on this:
http://www.livescience.com/15899-drinking-blood-safe.html
Composition of Blood
(source: snmjournals.org)
The following is multiple choice question (with options) to answer.
Which is likeliest to harm an organism? | [
"a naval mine",
"a short drizzle",
"eating a meal",
"a light breeze"
] | A | explosions can cause harm to an organism |
OpenBookQA | OpenBookQA-2251 | civil-engineering, water-resources
Title: Are detention ponds always dug? When creating a detention pond I have only came across examples where the pond is created by digging. Is it possible that a pond is created by creating retaining walls / embankments? and if it is can you please provide examples.
Please note! this is a detention pond not decorative pond. It is possible to construct a dam without digging a hole to form the dam, but earth must be brought in from elsewhere to create bund walls that will enclose the dam. In the past, the inside of the dam used to be lined with clay, to provide a leak proof seal. These days a polymer lining is placed in the smaller turkey's nest dams before filling it with water. Such dams are usually constructed on flat terrain and tend to be filled via a pipe or hose, generally attached to a pump.
From page 11 of Design of Earthen Tanks:
The turkey's nest tank is similar to the ring tank. But the material for the bund
construction is brought from the outer side of the bund. The level inside the tank is same as that
out side.
The following is multiple choice question (with options) to answer.
A pond that has gallons of water dumped in it daily will | [
"dry",
"grow",
"drain",
"shrink"
] | B | as the amount of water in a body of water increases , the water levels will increase |
OpenBookQA | OpenBookQA-2252 | homework, reproduction, allele
Title: Albinism inheritance problem: what are the father's alleles if he got an albino kid?
Albinism is caused by a recessive gen "c". A normal man marries an
albino woman. The first son happened to be albino. What are the
possible phenotypes of the parents? What is the chance that their
other kids will be albino?
Alright, since "c" is recessive and the woman is albino, then the woman must be "c c" right? And since the son is albino, he must be "c c" too. Hence the father must have at least one "c". But since he is normal, then the other allele must NOT be "c" too (otherwise he would be albino).
My question is, when writing the Mendel table, how do I express that allele of the father (the one that is not "c")?
$$\begin{bmatrix} & c & c\\
? & ?c & ?c\\
c & cc & cc\end{bmatrix}$$
I marked it with $?$ because I'm not sure what to put there. My first thought was "well, it could be a capital C I guess..." - but that doesn't sound right to me. A capital C would mean there is a dominant albinism allele (but I am told that albinism is recessive only...)
I can see clearly that there is a 50-50 chance of having albino kids. I just don't know how to draw that inheritance table. Super oober short answer: The father is Cc, the mother is cc, there is a 50% chance the children will be albino (as you predicted).
An explination on Mendelian genetics:
First let's look at (what a lot of people consider) the normal Mendel table from here:
The following is multiple choice question (with options) to answer.
Which of these is determined by heredity? | [
"If a plant produces gymnosperms",
"If someone has blue contacts in their eyes",
"If a child can build tall walls",
"If a plant receives enough sunlight"
] | A | the type of seed of a plant is an inherited characteristic |
OpenBookQA | OpenBookQA-2253 | zoology
Capybara, rabbits, hamsters and other related species do not have a complex ruminant digestive system. Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft fecal pellets of partially digested food are excreted and generally consumed immediately. Consuming these cecotropes is important for adequate nutritional intake of Vitamin B12. They also produce normal droppings, which are not eaten.
Young elephants, pandas, koalas, and hippos eat the feces of their mother to obtain the bacteria required to properly digest vegetation found on the savanna and in the jungle. When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to obtain any nutritional value from plants.
Eating garbage and human feces is thought to be one function of dogs during their early domestication, some 12,000 to 15,000 years ago. They served as our first waste management workers, helping to keep the areas around human settlements clean. A study of village dogs in Zimbabwe revealed that feces made up about 25% of the dogs’ overall diet, with human feces making up a large part of that percentage.
Coprophagia
Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: optimizing digestion through coprophagy
Coprophagia as seen in Thoroughbred Foals
The following is multiple choice question (with options) to answer.
Which of these animals might seek out the same type of food that a rabbit would? | [
"a lion",
"a cow",
"a wolf",
"a preying mantis"
] | B | rabbits eat plants |
OpenBookQA | OpenBookQA-2254 | geology, volcanology, mineralogy, minerals
Title: Where can obsidian be found? Where is obsidian found?
Is it typically found on the surface or underground?
If underground, how far under (meters or feet would be perfect)?
Also, is it found everywhere on Earth, or just in areas where volcanic activity is (or was recently) high? Obsidian is formed when a rhyolitic (or felsic) lava flows cool rapidly. This must mean that it's mostly available on the surface (and I think if you go near volcanos you can find pieces of Obsidian on the ground) because molten rock cools much faster above ground than it does below, allowing the melt to cool with small crystals (as opposed to intrusive rocks which have larger crystals). This means that Obsidian is an extrusive igneous rock.
I am betting that Obsidian is very common around most active volcanos around the world!
The following is multiple choice question (with options) to answer.
Lava is found above the ground because when there is lava there is | [
"a soft song",
"a frontal lobe",
"a small indent",
"a movement happening"
] | D | lava is found above the ground |
OpenBookQA | OpenBookQA-2255 | zoology, ornithology, ethology, behaviour
Title: Crow branch pecking behaviour I was walking through a small park when two crows started cawing at me, and followed me, flying from tree-to-tree as I walked. I speculate that this is a territorial or protective behaviour, but what I found different was the crows were violently pecking the branches nearby them. I have no memories coming to mind of seeing this behaviour beforehand. I speculate that this behaviour could be threat displays, but a quick search on Google did not reveal to me any authoritative studies on this phenomenon. I'd appreciate more information and sources.
This question has been added as a casual observation on iNaturalist. This is a good question. This type of behavior -- pecking at a branch, wiping the side of the beak on a branch, pulling off twigs and dropping them, or knocking off pieces of bark -- is quite common among many corvid species, particularly when they are interrupted by something or someone that they might consider a threat. This includes not only potential predators but also potentially hostile conspecifics.
It is typically considered to be a form of displacement behavior. The concept of displacement behavior, from classical ethology, posits that when an animal experiences two conflicting drives to do two different things, it doesn't know which to do and does a third thing instead to dissipate the drive or anxiety. For branch-pecking in crows, see E.g Kilham and Waltermire 1990 Ch. 12.
Referece: Kilham, L., & Waltermire, J. (1990). The American crow and the common raven. Texas A&M University Press.
The following is multiple choice question (with options) to answer.
Which of the following is an instinctive behavior? | [
"geese leave colder regions",
"a human boy learns to speak French",
"a chicken learns to play fetch",
"an eagle eats trash"
] | A | migration is an instinctive behavior |
OpenBookQA | OpenBookQA-2256 | evolution, zoology
Let's say the environmental challenge for two different kinds of carnivore (let's call them Bogs and Dats) is to catch Mophers. Both Bogs and Dats initially have the same medium-to-short muzzles. Some Bog individuals figure out that they can dig Mophers out of their burrows, and some Dat individuals figure out that they can catch Mophers at night when the Mophers leave their burrows. Both strategies are successful. Some Bogs happen to have longer muzzles than their cousins, and find it turns out that longer muzzles work synergistically with the digging strategy, allowing Bogs to stick their noses into the Mopher burrows to grab escaping Mophers. The resulting fitness advantage results in an increase of the long-muzzle trait in further generations of Bogs. Note that in this scenario it is the adaptive behavioral strategy that creates selective pressure that favors a particular genetic adaptation.
Dats on the other hand, because of their nocturnal hunting strategy, benefit from improved night vision; and long muzzles don't provide any fitness advantage to Dats because Dats don't dig Mophers from their burrows. As long as Bogs and Dats don't hybridize, they will most likely end up with long and short muzzles respectively.
The Waddington effect, also called “Genetic Assimilation”, is somewhat more direct:
An environmental stress causes a proportion of a population to develop one or more abnormal traits, by interfering with embryological development.
If there is a selective pressure in the environment that favors some subset of those traits, individuals whose genetic makeup makes them more likely to develop that subset of traits, those individuals are likely to produce more descendants than other members of the population.
If being “more likely to develop” that subset of traits results from a weakening of genetically determined development controls that would otherwise prevent development of that subset of traits, then the subset of traits can eventually become the normal phenotype.
The following is multiple choice question (with options) to answer.
A whitetail that lives in a forest will be required to adapt to | [
"long sleeves",
"harsh precipitation",
"silly anecdotes",
"boring movies"
] | B | changes in an environment cause animals to adapt to survive |
OpenBookQA | OpenBookQA-2257 | meteorology, climate-change, gas, pollution
Title: Regarding various types of atmospheric pollution Does all the car pollution (from about 150 million cars at least in the U.S. and a lot more in all of North America and the rest of the world) all the smoke-stack pollution of various factories and all the Airline pollution running day after day have a deleterious and damaging effect on the general atmosphere and, over time, the climate?
Given all the observed pollution that China has caused itself and some of the resulting weird weather events there this certainly seems to be evidence of the damaging effects of car and factory pollution. Has anyone calculated how much exhaust from cars is produced in one day on average in a 'moderate' sized city?
Of course it seems with all the increased oil production in the U.S. and elsewhere we, human beings are going to keep are love-affair with gas-powered cars for the next 200 or 300 years. That is if we don't use up all the oil and gas in the ground before then. As a USA resident, the EPA is the best place to start when wondering about the emissions inventory of atmospheric pollutants or pollutant precursors that affect the National Ambient Air Quality Standards (e.g. Particulate Matter, Carbon Monoxide, Sulfur Dioxide, Lead, Nitrogen Oxides, Volatile Organic Compounds). The EPA compiles a comprehensive emissions inventory of all criteria pollutants at the county level which is available in the National Emissions Inventory (compiled once every 3 years). You can see the summary of your county at http://www.epa.gov/air/emissions/where.htm. As for the effects of atmospheric pollution, it is important to consider the lifetime of said pollutants in the atmosphere in order to put their environmental impacts into perspective. For instance, the air pollutants covered by the National Ambient Air Quality Standards have immediate health effects when high concentrations are breathed in regularly. Both animals and plants are adversely affected by these irritating and sometimes toxic chemicals, but these pollutants are also reactive and do not last long in the atmosphere unless they are constantly being replenished (e.g. daily traffic). Air quality also impacts critical nitrogen loads on ecosystems and possible production of acid rain.
The following is multiple choice question (with options) to answer.
Which form of travel causes the most pollution? | [
"bicycling",
"skiiing",
"driving",
"walking"
] | C | using a car causes pollution |
OpenBookQA | OpenBookQA-2258 | quantum-mechanics, electromagnetism
Title: Can you magnetize iron with a hammer? We know that a piece of ferromagnet, such as iron, can be magnetized by putting in a strong magnetic field to get domains parallel to the field grow.
I also remember from pop. culture and MacGyver old tv series that you can magnetize a piece of iron by hitting it hard, with a hammer say, along the same direction.
1-Is this way of magnetizing iron scientific? or is it pseudoscience?
and if it is scientific then:
2-what is the physical principle that will allow iron to get magnetized by hitting? and
3-how about nonferromagnetic materials? Seems that it can be done, and here are instructions
Copying from the link
Strike an iron nail squarely and sharply several times with a hammer while keeping the nail positioned in a north-south orientation. The impact of the hammer with the iron nail causes the magnetic domains within the nail to break loose from their current orientation. The Earth's magnetic field will then reposition the domains into a new orientation parallel with the Earth's magnetic field.
It is evident that this can be done only with materials that have small domains with magnetization, which are randomly oriented, so the material has to be ferromagnetic.
The following is multiple choice question (with options) to answer.
Lodestones sharply yank metal nails because of | [
"allure",
"corrosion",
"irritation",
"evasion"
] | A | iron nails are made of iron |
OpenBookQA | OpenBookQA-2259 | career
Title: Data science career problems: interaction of technical and social difficulties I have been trying to break into the bioinformatics space (and now, data science more generally).
Although there are numerous challenges in this field and I am constantly learning to deal with them, I have have found the most consistent and intractible challenges are interpersonal, and they are unlike anything that my previous experience prepared me for. In particular, I find it very difficult to balance between getting the information I need (or think I need) to do a good analysis and maintaining productive relationships with people.
I have often had the sense that higher-ranking people than me were using their ability to act as gatekeepers of information to assert power over me, but it is almost never possible to be sure whether this is what is going on, or if I am making up excuses for my own lack of planning and follow-through.
A few examples.
The following is multiple choice question (with options) to answer.
If I yell out to a co worker which occupation would have a scenario where it is impossible to respond for scientific reasons? | [
"astronaut",
"lumberjack",
"fisherman",
"miner"
] | A | molecules vibrating can cause sound |
OpenBookQA | OpenBookQA-2260 | ichthyology, vertebrates
Title: If an organism is supported only by cartilage, does it have an endoskeleton? Lamprey and sharks lack bones, but does this mean they are not classified as having an endoskelton? Does an organism need bone to be considered as having an endoskeleton? From wikipedia
An endoskeleton (From Greek ἔνδον, éndon = "within", "inner" + σκελετός, skeletos = "skeleton") is an internal support structure of an animal, composed of mineralized tissue.
Cartilage is a mineralized tissue so it counts as a skeleton from this definition. A bit further in the wikipedia article it says
The vertebrate endoskeleton is basically made up of two types of tissues (bone and cartilage)
The following is multiple choice question (with options) to answer.
Which is most considered a part of the skeletal system? | [
"the gums",
"the femur",
"the skin",
"the lemur"
] | B | skeletal system is made of bones |
OpenBookQA | OpenBookQA-2261 | 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.
A person wants to get better acquainted with dogs, since they have a serious fear of them. This fear was probably | [
"scared",
"inherited",
"rare",
"learned"
] | D | preferences are generally learned characteristics |
OpenBookQA | OpenBookQA-2262 | 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.
A person pushing energy through a metal beam will cause something to | [
"electrify",
"crowd",
"hollow out",
"precipitate"
] | A | sending electricity through a conductor causes electricity to flow through that conductor |
OpenBookQA | OpenBookQA-2263 | evolution, mammals
Title: Why haven't land animals evolved beyond urination? It occurred to me (while urinating) that this would seem to be selected against because water is a scarce resource. Why are we constantly losing water we don't need to through urination? What is it about the chemistry of urine and the waste products eliminated that make urination necessary as opposed to eliminating them through defecation and recovering the water on the way out? It is probably true that toilets and other resting-ish area are always a great place to think about biology, I agree $\ddot \smile$.
Why do we urinate?
In short, urine contains the waste from our blood while defecation is just the stuff that we haven't digested. Kidneys are the organs responsible for draining wastes (mostly nitrogen-containing, or nitrogenous, wastes) from our blood.
Trade-off: energy cost vs. water loss
You're correct that the loss of water through urination is a considerable cost for an organism (especially those living in dry environments). But the amount of water used to excrete nitrogenous wastes is negatively correlated with the energy it costs to perform this excretion. In other words, there is a trade-off between water and energy loss during nitrogen excretion. Also, the question of toxicity is important.
Three ways to excrete nitrogenous wastes
Animals basically have three choices to excrete nitrogenous wastes:
Uric acid (excreted by uricotelic organisms)
Solid (crystal) with low water solubility
Low toxicity
Little water is needed
Lots of energy is needed
Ammonia (excreted by aminotelic organisms)
Highly soluble in water
High toxicity
Lots of water is needed to dilute it because of the toxicity
Not much energy is needed
Urea (excreted by ureotelic organisms)
Solid but highly soluble in water
"medium" amount of water is needed
"medium" toxicity
"medium" amount of energy is needed
The following is multiple choice question (with options) to answer.
Which of the following requires water to live? | [
"birds",
"dirt",
"soil",
"rocks"
] | A | living things require water for survival |
OpenBookQA | OpenBookQA-2264 | combustion
Title: Why are fires smokey? Combustion, in chemical terms, is a reaction with a certain molecule and oxygen, and it produces, energy, $\ce{CO2}$, and $\ce{H2O}$ (That's how I learned it at least). So what makes a fire'smokey'? I had always thought that smoke was simply $\ce{CO2}$, but read that it was actually the result of incompletely 'combusted' material, yet I don't fully understand what this means. Is smoke made from material that starts to combust but stops before it finishes, or does it never even begin combustion? What would the chemical reaction be of a wood (Or other similar) fire that produces a lot of smoke? And finally, is there a certain element or compound that gives smoke its 'smokey' smell? Smoke is essentially aerated ash, unburned organics (including charcoal) and steam. You have to remember wood is not a pile of cellulose, but the remains of a dead organism. All the essential minerals that the plant needed for life are still in the wood such as calcium, phosphorous, sodium and potassium (namely potassium). When the organic matter is fully combusted, water and carbon dioxide are produced and the other elements are left as ash which can become aerated. When the water vapor reaches the cool air it condenses into a visible steam. However in real life wood is not fully combusted, but rather many unburned organic compounds due to a limited amount of oxygen, which give it its smell and fine aerated particles of charcoal which is scentless but very dark. This presence of unburned hydrocarbons in smoke is the cause of backdrafts in firefighting and can be demonstrated by lighting the smoke of a candle that has been blown out.
The following is multiple choice question (with options) to answer.
A fire started in a forest but it wasn't started by people. What could have been the cause? | [
"a careless bird",
"a smoking bear",
"electricity",
"a campfire"
] | C | lightning can cause a forest fire |
OpenBookQA | OpenBookQA-2265 | human-biology, mammals, lifespan, dogs, rodents
Gigantism:
Whilst the life expectancy for a species may be higher in general people with gigantism may live shorter lives than possible because of non-metabolic related reasons. For example many forms of gigantism are linked to hormones which promote cell division and growth which are also linked to forms of cancer.
The following is multiple choice question (with options) to answer.
A creature that has developed to a certain age will be more likely to | [
"float",
"sneeze",
"fornicate",
"sing"
] | C | reproduction occurs during adulthood |
OpenBookQA | OpenBookQA-2266 | homework-and-exercises
Title: Is geothermal energy ultimately derived from solar energy? The following question is taken from 10th class science NCERT book chapter 14th.
Most of the sources of energy we use represent stored solar energy. Which of the following is not ultimately derived from the Sun’s energy?
(a) geothermal energy (b) wind energy
(c) nuclear energy (d) bio-mass.
The answer is given as (c) nuclear energy.
I understand that the wind moves because of the uneven heating of the earth by the sun. And biomass uses solar energy for photosynthesis.
How is geothermal energy ultimately derived from the sun? It is not a correct statement:
Geothermal energy comes from the heat within the earth. The word "geothermal" comes from the Greek words geo, meaning earth," and therme, meaning "heat." People around the world use geothermal energy to produce electricity, to heat buildings and greenhouses, and for other purposes.
The earth's core lies almost 4,000 miles beneath the earth's surface. The double-layered core is made up of very hot molten iron surrounding a solid iron center. Estimates of the temperature of the core range from 5,000 to 11,000 degrees Fahrenheit (F). Heat is continuously produced within the earth by the slow decay of radioactive particles that is natural in all rock
italics mine.
Geothermal energy comes from the original energy of the matter solidifying into the sun-planetary system, ultimately from the Big Bang, and from continuous nuclear decays and reactions .
The following is multiple choice question (with options) to answer.
Solar energy comes from the sun and does which positive thing? | [
"electrocutes birds",
"starves babies",
"freezes water",
"sustains mammals"
] | D | the sun is the source of solar energy called sunlight |
OpenBookQA | OpenBookQA-2267 | algorithms, graphs, optimization
There is one final component of your problem we have not addressed, i.e., there is a set of books $S_1$ that MUST go into box 1 and a set $S_2$ that MUST go into box 2.
Off the top of my head, I do not see a way to fix this without incorporating a source and sink $s$ and $t$ (for box 1 and 2 respectively). The formulation I've given above is almost sufficient. If $j\in S_1$ (book j MUST go into box 1), make $p_{sj}$ arbitrarily large (much more than $W$). This ensures an arbitrarily large cost will be charged if you try to but a book that must go into box 1 into box 2. Similarly, if $i\in S_2$, make $p_{jt}$ arbitrarily large.
Assuming $S_1$, and $S_2$ are non-empty (that books are already forced into each box), $W$ can be taken as 0 (since a proper partition is enforced by $S_1,S_2$) and $p_{sj}=p_{it}$ for $j\in S_1, i\in S_2$ can be as little as $\sum_{{i,j} \in N:\ i<j} p_{ij}$ (assuming each $p_{ij}\geq 0$).
The following is multiple choice question (with options) to answer.
A person who wants to avoid wasting a manufactured box will | [
"leave it at the dump",
"use it for new purposes",
"throw it in the trash",
"burn it in a fire"
] | B | An example of avoiding waste is using a material more than once |
OpenBookQA | OpenBookQA-2268 | Transcript
TimeTranscript
00:00 - 00:59so this is the question 1 ka manufacture compile data that the indicated mileage decrease in the number of the miles between driven between recommended serving increased the manufacturer use the equation Y is equal to minus one upon 200 X + 35 to model the data based on the information how many miles per gallon could be expected if the 34900 miles between servicing this is the graph which had been drawn using the best fit line from the scatter plots and the line equation of the line is given out here and it is asking for thirty four thousand miles over the combined with the recommended servicing recommended servicing MI is the x-axis and gas mileage in the wire we have been given the value of the x-axis and we have to calculate simultaneous simultaneous value of Dubai actors using this equation so
01:00 - 01:59Y is equal to minus x upon 200 f-35 X equal to 34000 ok so be divided out here 34000 / actually 3448 3430 4030 430 400/200 35 - 8 - 6235 we have to target for 3434 100 and 200 + 35 is equal to - 1700 gets cancelled 2134 also gets cancelled 17 times its - 17 + 35 it is equal to 18
02:00 - 02:5997035 equal to 18 18 mile gal idhar answer 18 miles per gallon thank you
The following is multiple choice question (with options) to answer.
A man had a car that only could travel for thirteen miles for every gallon of gasoline. His new car can travel forty miles for each gallon of gasoline. A trip that is fifty miles away will now require | [
"the same amount of gas",
"various amounts of gas",
"more gas than before",
"less gas than before"
] | D | as mileage per galon of gasoline increases , the amount of gasoline used will decrease |
OpenBookQA | OpenBookQA-2269 | c, game, console, minesweeper
// fill the mask
for(int y = 0; y < height; y++) {
for(int x = 0; x < width; x++) {
mask[y][x] = !EMPTY;
}
}
#ifndef DEBUG
for(int y = 1; y < height-1; y++) {
for(int x = 1; x < width-1; x++) {
mask[y][x] = EMPTY;
}
}
#endif
// temporary variables for mine locations
int coord_a, coord_b;
// initialize main field
for(int y = 0; y < height; y++) {
for(int x = 0; x < width; x++) {
field[y][x] = EMPTY;
}
}
srand(time(NULL));
//fill mines
for(int i = 0; i < mine_cnt; i++) {
coord_a = (rand() % (height-2)) + 1;
coord_b = (rand() % (width-2)) + 1;
//don't put mines in the same cell twice
if(IS_MINE(field[coord_a][coord_b])) {
i--;
continue;
}
field[coord_a][coord_b] = MINE;
}
//fill numbers one by one
for(int y = 1; y < height-1; y++) {
for(int x = 1; x < width-1; x++) {
// don't put a number if the current cell is a mine
if(!IS_MINE(field[y][x])) {
// looping the 3x3 adjacent cells
for(int dy = -1; dy <= 1; dy++) {
for(int dx = -1; dx <= 1; dx++) {
// skip the current cell
if(dy == 0 && dx == 0) continue;
field[y][x] += IS_MINE(field[y + dy][x + dx]);
}
}
}
}
}
return 0;
}
The following is multiple choice question (with options) to answer.
A person wants to mine something that will attract metals. The person decides to search out some | [
"ceramic stones",
"iron pebbles",
"glass beads",
"plastic beads"
] | B | iron is always magnetic |
OpenBookQA | OpenBookQA-2270 | 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 person wants to dry pips from sunflowers and then can plant those pips knowing that they have enough | [
"financing",
"nutriment",
"grain",
"solar wind"
] | B | a seed is used for storing food for a new plant |
OpenBookQA | OpenBookQA-2271 | reaction-mechanism, safety
Title: What are the consequences of mixing Ferric Chloride Solution, distilled vinegar, baking soda and water? I was attempting to etch and blade with a ferric chloride solution. I did not have enough so I filled a glass with vinegar and water (3 parts vinegar to 1 part water) then added 2 oz. of ferric chloride solution. I added baking soda later to neutralize the ferric chloride solution, but was met with a deep red foam. I quickly added more baking soda and flushed the solution down a deep sink in my basement. I rinsed out the sink and glass with water and continued to add baking soda to neutralize any ferric chloride solution that had been spread by the red foam. What reaction occurred and is this and do I need to worry about it? I suspect the red salt you are seeing is Iron (III) carbonate, which was likely created from, as you noted, the neutralization of aqueous Iron (III) chloride with Baking Soda (in excess?) per the reactions:
$\ce{FeCl3 (aq) + 3 NaHCO3 (aq)-> 3 NaCl (aq) + 2Fe(HCO₃)₃(aq)}$
$\ce{2Fe(HCO₃)₃ (aq) → Fe₂(CO₃)₃ (s) + 3H₂O (l) + 3CO₂ (g)}$
$\ce{2Fe(HCO₃)₃ + HAc (aq) → Fe₂(Ac)₃ (s) + 3H₂O (l) + 3CO₂ (g)}$
where the last reaction could also lead to Iron (III) acetate from the vinegar presence, which is also subject to further neutralization by the Baking Soda.
The following is multiple choice question (with options) to answer.
Which of the following results from a chemical reaction involving baking soda? | [
"Mixing play-doh",
"Making cereal",
"A dog's saliva",
"Science fair volcanoes"
] | D | baking soda can react chemically with vinegar |
OpenBookQA | OpenBookQA-2272 | metals
Title: Why does carbon alloy with iron specifically? Everyone knows what an alloy is: it's a metal made by melting two (or more) other metals together.
Unless of course you're talking about steel. That's a metal made by mixing carbon (very much not a metal) into molten iron. But you never hear about carbon alloys with any other metal, and that's kind of strange. If a few percentage points of carbon can turn iron into the miracle metal that is the foundation of the Industrial Age, just imagine what it could do to aluminum or titanium, for example. (Or even bronze, for that matter, which is superior to iron in many ways, from a materials science perspective.)
But you only ever hear about carbon alloying with iron to form steel. So what's so special about iron? It's true they are not common, but there are other alloys that use carbon. Nickel is probably one of the more common metals that form alloys with carbon that have desirable properties. For example, Nickel 200, Nickel 201, and Nickel 205 all contain carbon. (See: http://www.asminternational.org/documents/10192/1852239/ACFA9D7.pdf/d490dee6-620e-4e38-b64d-53dd02c5fc81). Chromium and Tungsten also form alloys with carbon called Stellite Alloys: See http://en.wikipedia.org/wiki/Stellite (although some, but not all, stellite alloys contain iron too).
The following is multiple choice question (with options) to answer.
Ferrous metals can comprise items such as | [
"steel clogs",
"gold cats",
"bronze shoes",
"Fe armor"
] | D | ferrous metals contain iron |
OpenBookQA | OpenBookQA-2273 | javascript, performance, datetime, node.js, matrix
Title: Net health monitoring This is a little net health monitoring project I made in NodeJS. It pings Google every second and stores the result (true/false) along with the date in a database (MongoDB). I've collected enough data and I want to represent it for the past week.
I created a 2x2 array of 7 days and 24 hours each. I go through each record and map it to the appropriate day and hour of the week. And I give that hour a little score: if true +1, if false -5. And it creates a little matrix like this:
[
[2015, 1724, 1733, 1679, ...
[1818, 1909, 1614, 1829, ...
[1632, 1778, 1726, 1657, ...
...
]
The only problem is computation takes ~10-15 seconds and lots of CPU for going through ~200k records of just 3 days.
Is there some scope for improvement here?
days = days || 3;
var counter = 0
this.find({
date: {
// Date greater than (Now - X days)
$gt: new Date(Date.now() - days * 24 * 3600 * 1000),
},
}, function(err, datums) {
var week = new Array(days);
for (var i = 0; i < week.length; i++)
week[i] = new Array(24);
// Empty Week Matrix (7x24)
datums.forEach(function(data) {
counter++;
var date1 = data.date;
var date2 = new Date();
var timeDiff = Math.abs(date2.getTime() - date1.getTime());
var diffDays = Math.ceil(timeDiff / (1000 * 3600 * 24));
//stackoverflow.com/q/3224834/1266650
var day = days - diffDays;
if (day < 0) return;
var hour = data.date.getHours();
The following is multiple choice question (with options) to answer.
A person wants to discover how much time they've spent on something, so when they think about data, they need to | [
"accumulate it",
"ignore it",
"lose it",
"forget it"
] | A | An example of collecting data is measuring |
OpenBookQA | OpenBookQA-2274 | because the balloon is a sphere, we know. Imagine that you are blowing up a spherical balloon at the rate of. Formulas for Model Hot Air Balloon Lift: Gross lift is the weight of the ambient air minus the weight of the heated air. The volume of a sphere with radius r is (4/3)πr^3 and the surface area is 4πr^3. 11" round latex balloons at 5280' will become 11 1/4" balloons at 7500' (assuming spherical balloons, this is more than a 2% increase in diameter, since diameter scales as the cube root of volume for a sphere. Let A be the area of a circle with radius r. find the rate of change of the radius when the radius is 2 feet. The volume of the composite figure is the sum of the volume of the cone and the volume of the hemisphere. DISCUSSION The step-section planimetry method of volume determination is accurate (correlation coefficient 0. Spherical Pressure Vessels Shell structures: When pressure vessels have walls that are thin in comparison to their radii and length. Given James' golf ball has a radius of 1. From inside, it was white-washed at the cost of Rs. Recall that the formula to get the volume of a sphere is V = (4/3) × pi × r 3 with pi = 3. Largest Volume for Smallest Surface. If a balloon and a scuba tank are both filled with air and placed outdoors in direct sunlight on an. cal coordinates. In mathematics, a hexagonal prism is a three-dimensional solid shape which have 8 faces, 18 edges, and 12 vertices. 3 What is the volume of a spherical segment of a sphere of one base if the altitude of the segment is 12cm. For example, we can measure volume in cubic feet and time in seconds. Find a function that represents the amount of air required to inflate the balloon from a radius of r inches to a radius of r+1 inches. OP is the radius of the sphere. 1) A balloon has a volume of 1. The spherical formula 7r/6 (transverse dimension)3 was most accurate for glands weighing more than 80 gm. A sphere is a perfectly round shaped object and has no edges and vertices. surface area S= 4ˇr2. So,enter r and hit the calculate button to get the volume The calculator will only accept positive value for r. DISCUSSION The step-section planimetry method of
The following is multiple choice question (with options) to answer.
A person can inflate a beach ball using | [
"a salt shaker",
"several cups",
"live bees",
"organ processed gas"
] | D | a beach ball contains gas |
OpenBookQA | OpenBookQA-2275 | organic-chemistry, reaction-mechanism, alcohols
The primary carbon will not, as stated above, form a primary carbocation since it is too unstable. Hence only the bimolecular substitution will occur. If no primary carbocation is generated, no Wagner-Meerwein rearrangement can occur. And the mechanism of an $\mathrm{S_N2}$ reaction does not allow bromide’s (or anything else’s) migration.
The secondary carbon could undergo bimolecular substitution, too. The reaction rate will probably be slower than that of fragmentation and rearrangement, though, since the latter are unimolecular processes. And other shifts (e.g. methyl followed by hydride) are possible but again slower since you need to shift twice. All in all, a higher proportion of side-products may be expected.
In no case will the bromide shift after substitution; any shift would need to occur before.
The following is multiple choice question (with options) to answer.
Which would likely result in a chemical change? | [
"a piece of paper in marbles",
"a piece of meat submerged in lemon juice",
"a blade of grass in sand",
"a piece of cotton in water"
] | B | An example of a chemical change is acid breaking down substances |
OpenBookQA | OpenBookQA-2276 | entomology
Title: What is the name of this tiny creature? It looks like a tiny piece of moving cotton? By chance, I saw this tiny insect on my bag a few days ago in Sydney. Am I the first person who has pinpointed this animal?! If not can you please let me know its name? From your image, it looks like it might be a woolly aphid. I just did a bit of cursory research, and it looks like they're often described as floating pieces of fluff, that seem to wander instead of directly heading somewhere. The fluff on their back is actually wax produced as a defense mechanism from predators and the like. I hope this is what you were looking for!
The following is multiple choice question (with options) to answer.
A person wanting to attract striped insects to come and feed in their yard would display | [
"birds",
"tuna",
"knives",
"carnations"
] | D | bees eat pollen |
OpenBookQA | OpenBookQA-2277 | fusion, renewable-energy
An energy "breakthrough" would be a loaded development. We already use lots of energy, and if we found it economic to use more we probably would. The last breakthrough shift in our ability to exploit energy resources rocketed the entire planet into a new geological era, the Anthropocene. We called this change the industrial revolution. Some obscure project that ARPA-E funded with $500,000 could cause the next industrial revolution. The implications of such a change would probably be beyond any of our imaginations.
The following is multiple choice question (with options) to answer.
The diminishing supply of this nonrenewable resource is leading to advancements in automotive technology | [
"petrol",
"coal",
"trees",
"steam"
] | A | fossil fuels are a nonrenewable resource |
OpenBookQA | OpenBookQA-2278 | meteorology, snow, radar
Also note that winter precipitation adds an extra complication because the particles are lighter in weight and can thus be blown about more by vertical and horizontal winds. Raindrops (and hail) are quite likely to fall unless extreme updrafts exist because they are heavy. But drizzle, snow, and sleet may be blown around quite a bit. Without a time-intensive dual-Doppler analysis, you cannot know the wind motion in the storm thoroughly, and therefore will have varying results at times.
And finally, the big wrench is unfortunate inherent to how radars work. They measure the percentage of their sent energy that is reflected back to them. That's great because that's directly connected to the diameter of the item falling (to the 6th power). But unfortunately the grand problem is that in a storm, there is a huge variety of drop/flake sizes mixed together at once... such that we can't extract which combination of particle sizes created it (and thus can't calculate volume to actually know the rain/snow amount that falls). It could be like 6 medium size flakes causing the 10 dBZ echo... or 2 large flakes and 10 small flakes... and each combination is a different volume/snow total. (to see the nitty-gritty math details on this, read more here.) So we can never know for sure the exact rain/snow falling using just radar. The good news is we've at least done lots of experiments and come up with some fairly useful best-practice formulas for using the Z-R ratio in different scenarios. Good, but not perfect.
The following is multiple choice question (with options) to answer.
A storm is covering a town in sleet, which means that things | [
"will be dry",
"will be burning",
"will be slick",
"will be toasty"
] | C | sleet is made of ice |
OpenBookQA | OpenBookQA-2279 | thermodynamics, heat-engine
You have your flame power the $`` {\small{\begin{array}{c} \textbf{Hot Water} \\[-25px] \textbf{/ Steam} \end{array}}} "$ stream. This step is how we input the excessive driving force that comes from the flame's unnecessarily high temperature.
You hook up some random waste heat source to the $`` {\small{\begin{array}{c} \textbf{Chilled} \\[-25px] \textbf{Water} \end{array}}} "$ stream. When the contents of this stream go through the $`` \textbf{Evaporator} " ,$ they'll give off their heat to evaporate the heat pump's internal working fluid – and, since the that internal working fluid is stealing the stream's thermal energy, that stream is cooled in the process. This step is where we get the extra thermal energy from.
You hook up whatever you want to heat, like the air to your home or the food you want to cook, to the $`` {\small{\begin{array}{c} \textbf{Cooling} \\[-25px] \textbf{Tower} \end{array}}} "$ stream. As the contents of that stream flow through the absorber, the internal working fluid is reconstituted in an exothermic reaction, warming the contents of the stream. The warmed stream then exits the heat pump, only to reenter it in the condenser. In the condenser, the gaseous internal working fluid condenses on the stream, again dumping heat into it (as condensation is also exothermic).
If you do a thermal-energy balance on the system, you'll see the the thermal energy from the flame and the waste-heat source both ended up warming your home/food/whatever. In effect, you got more thermal energy out of the flame than the flame actually had by using its excess driving force to also harvest thermal energy from a waste heat source.
possibility of a “reverse-refrigerator” that cooks?
The following is multiple choice question (with options) to answer.
Heat energy may be added to this in order to cook it. | [
"velvet socks",
"fish food",
"dish water",
"cupcake batter"
] | D | if food is cooked then heat energy is added to that food |
OpenBookQA | OpenBookQA-2280 | species-identification, botany
Title: Can you identify this (possibly waterstoring) plant? My son brought home a sapling, and after 4 years in a pot it is now about 30 cm or a foot high (from the "ground" to the top of the "stem"). It doesn't need a lot of water and can go weeks without being watered, in fact it seems to me as if it is storing water in the thicker upper part of its stem. When I water it "too much", new leaves start to grow. There are tiny "blossoms" along the stem, and every now and then small, dark brown, spherical seeds about 2 mm in diameter pop out from the "blossom" and are thrown across the room as far as a meter (about a yard) or two.
What plant is this?
I believe that it is not native to my European home but some kind of decorative plant imported and sold through a florist or imported privately, but I'm not sure. It is an Euphorbia leuconeura (Madagascar Jewel), which is native to Madagaskar. The leaves and the thick (waterstoring) stem with a narrow base is very typical.
The plant is cool in the sense that it easily produces seeds (also as potted) which it can shoot away from the plant. I've had it myself and you can sometimes hear seeds hitting the window or floor. Even if it is easy to grow and to reproduce it is actually considered threatened in its native habitat (IUCN Red-listed as Vulnerable) due to habitat loss
The flowers are very small and found directly on the stem, see below:
(picture from Wikipedia)
The following is multiple choice question (with options) to answer.
A plant that using transpiration is | [
"filtering liquid nicotine",
"adjusting water content",
"evaporating oils",
"flavoring leaves"
] | B | plants control the amount of water in their leaves through transpiration |
OpenBookQA | OpenBookQA-2281 | newtonian-mechanics, estimation
Would the rock have created a seismic event of its own (if so, how large)?
Would the rock have created a crater? The energy of the rock at the time of hitting the earth is mgh.
No rock we know of is going to be able to survive this collision with out breaking into pieces.
Non the less it will be a big impact and depending on the geology of the location it hits a variety of reactions scenarios can happen.
If the soil is aggregate of silt and sand and gravel, it would part into several shear rupture sections which look like slices of shell pattern surfaces starting from the bottom surface of the rock and turning up exiting the earth surface a few hundred yards outside of the impact zone and probably even eject some material out like a bomb crater. This scenario will have shakes that could be recorded miles away.
The calculation of how much of the momentum of rock will be shared with the shear material and accelerating them will be involved but not impossible.
If the geology of the impact area is of very low bearing like mostly silt and loose clays, the rock my lose most of its kinetic energy by just sinking into the dirt mostly with a giant humph with a cloud of dust rising.
If the geology is hard or rocky with the 'optimal' amount of mass and resilience it could create a substantial earthquake by resonating with the impact.
The following is multiple choice question (with options) to answer.
A load of earth and stone that folds upon itself repeatedly could be considered | [
"a still",
"a group",
"a range",
"a pond"
] | C | mountains are formed by plate tectonics |
OpenBookQA | OpenBookQA-2282 | botany, plant-physiology, plant-anatomy
*No others are known, but could definitely exist.
Bibliography
Crafts, A. S. “Phloem Anatomy, Exudation, and Transport of Organic Nutrients in Cucurbits.” Plant Physiology 7, no. 2 (1932): 183–225.
Fischer, A. “Das Siebröhrensystem von Cucurbita.” Berichte Deutsche Botanische Gesell 1 (1883): 276–279.
Fischer, A. “Neue Beiträge Zur Kenntniss Der Siebröhren.” Berichte Über Die Verhandlungen Der Königlich-Sächsischen Gesellschaft Der Wissenschaften Zu Leipzig, Mathematisch-Physische Klasse 38 (1886): 291–336.
Fischer, A. Untersuchungen Über Das Siebröhren System Der Cucurbitaceen. Berlin, 1884.
Turgeon, R. and Oparka, K. “The Secret Phloem of Pumpkins.” Proceedings of the National Academy of Sciences 107, no. 30 (2010): 13201 –13202.
Walz, C. and Giavalisco, P. and Schad, M. and Juenger, M. and Klose, J. and Kehr, J. “Proteomics of Curcurbit Phloem Exudate Reveals a Network of Defence Proteins.” Phytochemistry 65, no. 12 (2004): 1795–1804.
Zhang, B. and Tolstikov, V. and Turnbull, C. and Hicks, L. M. and Fiehn, O. “Divergent Metabolome and Proteome Suggest Functional Independence of Dual Phloem Transport Systems in Cucurbits.” Proceedings of the National Academy of Sciences 107, no. 30 (2010): 13532.
The following is multiple choice question (with options) to answer.
Which of the following organisms uses what is referred to as system of tubes to transport water and nutrients? | [
"a shark",
"a panda",
"a bamboo stalk",
"a human"
] | C | a plant stem contains a system of tubes for transporting water and nutrients to other parts of the plant |
OpenBookQA | OpenBookQA-2283 | climate-change, geography, rivers, rainfall, agriculture
Today Climate change and its consequences are some of the biggest challenges facing Humanity, with water scarcity being the big factor in Sub-Sahara Africa.
By Ultimately raising the Rainfall in the entire Southern Africa, through the managed and controlled filling and utilization of the Natural 30 000 - 60 000 square km of evaporation pans more regularly, will this not lower the extreme temperatures (day and night temperatures due to water absorbing much of the daytime heat and releasing it during the night) and drought patterns Southern Africa has experienced, and by all predictions are bound to worsen and could become more extreme?
In effect, creating a second Okavango Delta, but considerably bigger - large parts of Chobe.
A study of such a magnitude will need large amounts of research in multidisciplinary sciences, from Archaeology to Agriculture to Economics, and a much broader field of expertise - the biggest being Politics!
Could such a mammoth project not be but one small answer to a much bigger Climate Change challenge facing the Earth? (and ultimately send a bit of rain to my little piece of land in the Waterberg in the long dry winter months when we receive those dry West Winds - and fires become a serious hazard - simply by adding a bit of moisture from the vast pans Botswana are so blessed with!)
My mind has been going in circles as to the feasibility of such a mammoth, yet so cheap and easily implementable idea?
Any ideas? We agree that additional evaporation enhances energy transport from the surface to the atmosphere and intensifies the hydrological cycle and cloud formation, and that some of the most serious climate change issues such as:
The following is multiple choice question (with options) to answer.
An area of land has more rainfall, producing more plants of various species. The plant boom causes | [
"a hydrogen explosion",
"a boosted ecosystem",
"a crying child",
"an extreme drought"
] | B | as the number of sources of food increase in an environment , the population of the organisms will increase in that environment |
OpenBookQA | OpenBookQA-2284 | sun, vision, biology, eclipse, laboratory-safety
Title: Why aren't 100% UV blocked sunglasses safe to view an eclipse with? I am not planning on staring into the sun during an eclipse or any other time.
I have been reading about how no variety of regular sunglasses are safe enough to view the eclipse with. I'm not talking about being able to see things clearly, but just actual eye safety.
From what I understand it is the ultraviolet light that causes damage to the retina, but maybe it is more complicated.
How do my eyes get hurt if I am looking at the sun through so called "100% UV protection" and what makes the eclipse glasses sold in stores different?
edit: To clarify this is not about how the rays from the sun are dangerous, but about why "100% UV blocking" sunglasses fail. Do other dangerous rays get through? Is the "100%" marketing? Essentially, in what way are the best consumer sunglasses inadequate for looking at an eclipse.
Answers about pupil dilation and what makes an eclipse more dangerous for naked-eye viewers are not what I'm after. You are correct that almost always it is the UV content of sunlight and not its power that is the main hazard in staring at the Sun.
The lighting during a total eclipse is one of those situations outside the "almost always". Eclipses did not weigh heavily on our evolution, so we are ill kitted to deal with them.
Moreover, UV sunglasses are not designed to attenuate direct sunlight, only reflected sunlight.
Normally, the eye's pupil is shrunken to about a millimeter diameter in bright sunlight. This means that it admits about a milliwatt of sunlight, which, for healthy retinas, is nowhere near enough to do thermal damage (see my answer here for further discussion).
During an eclipse, the pupil dilates to about $7\,\mathrm{mm}$ diameter to adapt for the low light levels of the eclipse's twilight. Thus its aperture is fifty times bigger than it normally is in sunlight. This means it admits a great deal more UV than normal (and the corona, at $100\,000\,\mathrm K$, radiates a great deal of this). You're getting about $50$ times the dose you would normally get even looking directly at the Sun.
The following is multiple choice question (with options) to answer.
Which would damage the eyes the most in a laboratory setting without protection? | [
"a stray cat",
"an acidic spray",
"a chainsaw",
"your thumb"
] | B | chemical splashing can cause harm to the eyes |
OpenBookQA | OpenBookQA-2285 | optics, visible-light, reflection, refraction
As apparently we are able to see blue and weak, but clear violet stripe in the rainbow, my understanding is wrong. So why don't we get red, yellow, green and blue light in it as well? Why do we see spectrum as if we were using prism, not the "cumulative spectrum"? With the addition of some good diagrams I think I now understand your question.
This diagram does not show a key feature of the reflections.
The intensity of the reflected rays varies and so you do not observe a uniform cone of reflected light.
Here is a gif animation to show you what I mean.
[Individual images were taken from an Atmospheric Optics webpage and combined to produce a gif file.]
Parallel rays are coming in at the top of a water droplet and refracted, reflected and refracted again to emerge from the bottom half of the drop.
What you should note is that for a given range of impact parameters of the incident rays the highest concentration of emergent rays occurs occurs around an angle of $137.5^\circ$, ie that is where the emergent light is brightest and light from around that angle swamps the light from that emerging at other angles.
So you diagram should show a high intensity of red light around a particular direction and and much lower elsewhere.
Here is a ray diagram to illustrate the "bunching" of light rays along a particular direction.
The following is multiple choice question (with options) to answer.
Which of the following reflects the most light? | [
"snow",
"root beer",
"coal",
"the night sky"
] | A | if an object reflects more light then that object is more easily seen |
OpenBookQA | OpenBookQA-2286 | zoology, microbiology, pathology
Title: Prevention of disease spreading in animal kingdom It's my first question on here, so I'm not sure If my question fits the theme. Please refer me to the appropriate one, If I have made a mistake.
So a question that I wanted to ask has to do with whether or not animals potentially try to avoid spreading diseases. So I was thinking... In an event that a really deadly disease emerges in a population, it would be really dangerous for animals that live in social groups, of any size really, not to have any instinctual behaviours that try and prevent the disease to spread. Animals that live in big heads, like wildebeests would just probably leave the diseased individuals behind, apes and monkey could potentially cast out individuals from the group, etc. Ants have separate sections in their tunnels that serve as graveyards, I presume for this exact purpose.
A lot of parasitic organisms have adaptations that specifically target animals with social behaviour, so why wouldn't animals adapt against that?
Something that also came to my mind is that this could possibly evolve not as a social behaviour of a group, but sometimes that individuals in a group would do, for example self isolation. However, I do not find this likely, I possibly requires higher cognitive understanding of disease spread.
Am I way of base here? If not, could you please provide some interesting examples you are familiar with.
The following is multiple choice question (with options) to answer.
To protect themselves from consumers, which action would an animal most likely take? | [
"nesting right beside predators",
"standing out in the sun",
"standing out from the environment",
"appearing the same as surroundings"
] | D | camouflage is a kind of protection against consumers |
OpenBookQA | OpenBookQA-2287 | machine-learning, neural-network, reinforcement-learning, q-learning
This average expected reward is not really the value function $V$ we are interested in estimating. Our target $V$ should tell us the best expected reward for each position, after all. Interestingly, though, when your policy is already optimal then your average reward is equal to your optimal reward (because you always do optimal moves anyway), hence it may be the case that even though you are kind-of learning the wrong metric in your algorithm, if the learning process pushes your algorithm ever so slightly towards optimal play, as you gradually improve your policy, the "average expected reward" metric itself slowly becomes "more correct" and eventually you start converging to the correct value function. This is pure handwaving, but it should illustrate the claim about it being hard to prove or disprove whether your algorithm formally learns what it should learn. Maybe it does.
In any case, let us, instead of tracking the average reward for each state, change your algorithm to track the best possible reward so far. This means, you'll check all the alternative moves from each position and only update $R(s)$ if your current move resulted in an improved score down the road (in comparison to alternative options you could have taken from this state). Congratulations, now your algorithm is equivalent to the usual Q-learning method (it is the "value iteration" method, to be more precise).
Finally, "is it learning or brute force" is a valid question. The word "learning" can be interpreted in at least two different ways. Firstly, learning may denote simplistic memorization. For example, if I discover that the first move to the center is good, I may write this fact down in a table and use this fact later directly. People call such memorization "learning", but this learning is really quite dumb.
A second, different meaning often ascribed to "learning" is generalization. It would be the case when, besides simply writing down which moves are good, your algorithm could generalize this information to previously unseen moves. This is the "intelligent" kind of learning.
The following is multiple choice question (with options) to answer.
Which would be considered a learned behavior? | [
"birds building nests",
"cats making hairballs",
"dolphins' echolocation",
"dogs playing fetch"
] | D | if an animal is trained to do something then that something is a learned behavior |
OpenBookQA | OpenBookQA-2288 | species-identification
Title: What species is this worm? I was at the park lying on the grass and its the third time I have seen them, I used to think they were parasites when I was like 7. It is the very small brown worm on the green leaf. It moves by squiggling. It comes in different colors but same size.
http://postimg.org/image/ea3x2nw95/
http://postimg.org/image/zfawh9pr1/ For me it looks like an inchworms which are the larvae of geometer moth or Geometridae.
By your picture it is almost impossible to see of which type it is.
I took picture of one in Switzerland (but likely not the same as yours).
Full resolution here: https://flic.kr/p/utFsiU
The following is multiple choice question (with options) to answer.
A worm would most likely be eating | [
"a living tree",
"a healthy human",
"a dead lizard",
"a living rat"
] | C | dead organisms decay |
OpenBookQA | OpenBookQA-2289 | geology
Title: Where do riverbed stones come from? Have they always been here since the river was formed? Are some newer than others? Riverbed 'stones' - I assume you mean things like pebbles, boulders, etc. are pieces of rock that have weathered out and been deposited in the river. Some come from rock that is very close to where they are located and some have been transported from very far away. In general (and it is a very broad generalization) the rounder the stone, the longer it has been in the river and the more likely it is to have come from far away. Of course that depends on the hardness of the rock, and other factors, too.
Some rocks are newer than others. Some have been formed quite recently and some are billions of years old.
The following is multiple choice question (with options) to answer.
A beach had large stones on it several decades ago. Now, after years of rough winds, the beach is mostly | [
"jungle brush",
"enormous boulders",
"tiny grains",
"tall trees"
] | C | wind causes erosion |
OpenBookQA | OpenBookQA-2290 | geophysics, sedimentology
Title: Does dirt compact itself over time? If so, how does this happen? If I were to bury something 10 feet (~3 metres) underground, with loose soil on top, would the ground naturally compact itself over time, until whatever I had buried has dirt tightly pressing against it on all sides?
What if I buried it 50 feet (~15 metres) underground?
If it exists, what is this compaction process called and how does it happen? Soil is a collection of various sized minerals grains, of various types of minerals produced by the weathering of rock. Typical soil minerals are clays, silts and sands.
The properties and behavior of different soil types depends of the composition of the soil: the proportion of clays, silts and sand in a soil. Sandy soils are well draining and clayey soils are sticky.
Between the grains of minerals that comprise a soil are spaces, called pores or pore spaces. The pores can be filled with either water or air, depending the location of water tables and wetting events like rain, snow melts or other forms of water inundation.
The density of a soil is dependent on the degree of compaction of the soil. For to a soil to be compacted, a stress has to be applied to the soil to realign the grains of soil which reduces the total volume of the pores and reduces the amount of air within the pores.
Consolidation of a soil occurs when pore space is reduced and water in a soil is displaced due to an applied stress.
Regarding having something buried and soil compacting around it over time, yes that will occur but it is a question of how much stress the soil experiences, the duration of time and the nature of the soil - sandy or clayey. Something buried for a day without any stresses not much will happen. But, something buried for thousands of years with people and animals walking over it, rain falling on the soil, vibrations from nearby human activity and an occasional earthquake all add to the stresses the soil will experience and increases the degree of compaction or consolidation over time.
The following is multiple choice question (with options) to answer.
A person drops a bean in the dirt, and kicks some dirt over it. If the person goes to dig up that bean a month later, it is likely to have | [
"shrunk",
"sprouted",
"burned",
"flown"
] | B | seeds may sprout when buried in soil |
OpenBookQA | OpenBookQA-2291 | 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.
Which would be a source of pollutants? | [
"cars",
"oceans",
"glaciers",
"storms"
] | A | pollution is a source of pollutants |
OpenBookQA | OpenBookQA-2292 | waves, atmospheric-science, turbulence
The clouds form if the rising air reaches the lifted condensation level before the updrafts are stopped by an inversion or stable layer. The air is (relatively) clear above the downdrafts. If the convection rolls were perfectly circular, the cloud row spacing would be twice the height of the inversion/stable layer.
Mathematically, there are many wavelength solutions to convection, but the wavelength that dominates is the fastest growing one. In the Boussinesq approximation, which is reasonably valid here, this turns out to have a wavelength of $2\sqrt{2}\sim 3$ times the height of the convecting layer, i.e. slightly flattened. (See, for example, Eq. 21 of Kuettner (1971) "Cloud bands in the earth's atmosphere: Observations and Theory".)
For typical cumulus cloud heights of $\sim 2$ km, we expect typical spacings of about $6$ km.
Wave, lee, or mountain clouds are lines of clouds downwind of an obstacle (such as a mountain range). The lines are parallel to the wind direction. These are buoyancy waves where wind pushes denser air over an obstacle (e.g. a mountain range) and it ends up above less dense air on the other side. This dense air starts to fall but it overshoots into even higher density air at lower altitude, which forces it back up, and the air ends up bouncing up and down until the oscillations die out. If the vertical temperature profile of the air then is known, it is possible to estimate the vertical buoyancy angular frequency
$$N=\sqrt{\frac{g}{\theta}\frac{d\theta}{dz}}$$
The following is multiple choice question (with options) to answer.
Which of these most closely resembles how clouds come into being? | [
"making beer",
"distilling liquor",
"driving a car",
"baking bread"
] | B | water vapor condensing in clouds causes rain |
OpenBookQA | OpenBookQA-2293 | behaviour
Title: What happens to silverfish when we throw them out the window? I'll find a silverfish from time to time in my flat. I don't mind them but usually I catch them and throw them off the balcony (second story) into the bushes and lawn below.
I was wondering, since they seem to live in the water conduits in the house, if they can survive outside or if they die/get killed instantly.
Thx for your help! Silverfish prefer high humidity and warmth. Ctenolepismacalvum (Ritter, 1910) was recently found in Japan at a temperature of 20-30°C and 50-60% RH. As long as there are pieces of bark, wet grass or other organic or human-made structures that retain humidity after each raining event, the likelihood that they will survive long enough to complete their cycle is high.
They could face dessiccation if they are not able to find a damp spot in time, depending on their tolerance to it. However, it was not possible for me to find information about their dessiccation tolerance.
The Zygentoma (silverfish order) have high tolerance to low humidity and most of the species inhabit dry and hot environments (it's just a few that like humidity), which again makes me think that those silverfish propelled out the window will survive.
The following is multiple choice question (with options) to answer.
A bird species may decide to relocate to hotter areas when weather | [
"sears",
"cools",
"warms",
"burns"
] | B | migration is when animals move themselves from a cooler climate to a warmer climate for the winter |
OpenBookQA | OpenBookQA-2294 | 2) Let $X$ be the largest possible set satisfying the question, supposing it exists. Is there a simple way to calculate its boundary, $\partial X$?
3) What is the volume of the largest possible set in question in terms of $A_i$? It's worth noting that, if $A_1, A_2, A_3$ are measurable subsets of $I^2$, then there is an interesting formula for the volume of $X$ plus the volume of $Y = I^3 - \pi_1^{-1}(A_1) \cap I^3 - \pi_2^{-1}(A_2) \cap I^3 - \pi_3^{-1}(A_3) \cap I^3$.
• Do you require the set to be connected, as the two subsets are on the book cover? – Brian Tung Aug 10 '17 at 20:18
• @B.Goddard 3D printing should be no problem, but of course wood-cutting would be much more impressive. – Hagen von Eitzen Aug 10 '17 at 20:21
• Interesting question! But as usual, I would be more interested in the practical computation of one. Can we maybe define some differential or integral equation that incorporates the question? – mathreadler Aug 10 '17 at 20:26
• @DeanYoung "It is natural to ask for generalizations". What are you, a mathematician? :-) Seriously, nice question, +1. – MarnixKlooster ReinstateMonica Aug 11 '17 at 15:39
• I am not sure how this is a question about set theory (elementary or otherwise). – Asaf Karagila Aug 12 '17 at 21:46
The following is multiple choice question (with options) to answer.
Which can be said to have the most volume? | [
"the Sun",
"Venus",
"the moon",
"the Earth"
] | A | the volume of an object can be used to describe the size of that object |
OpenBookQA | OpenBookQA-2295 | thermodynamics, geophysics
With supercooled water, this effect is even more pronounced - a water at -30 °C has about the same density as water at 60 °C.
Oceans cool mostly by evaporation - the surface layers of water "spontaneously" changing state from liquid to gaseous. You get a balancing act between energy lost to evaporation, and incoming sunlight. However, there's a huge gap between the surface and the deeps, a lot of water mass - the incoming sunlight is nowhere near enough to warm ocean waters throughout. So you get warm surface waters, then a gradient of cooler and cooler water, and finally about 0-3 °C in the deep. To illustrate how big this gap is, about 90% of the worldwide ocean water is in the 0-3 °C range (hence the "nowhere near enough sunlight to heat the whole thing through").
Of course, a 4 °C body of water is great for cooling systems running at 40 °C and more. Air is actually a pretty good insulator, so air cooling gets tricky with large systems. Water, on the other hand, is pretty thermally conductive, and it easily convects, so cooling a huge data centre becomes almost trivial.
EDIT:
Let me address the Sun part, since there seems to be some confusion there as well.
Nuclear fusion is something that happens very infrequently. Two nuclei must come very close together to fuse, and they need enough kinetic energy to overcome the repulsion between each other (since both have the same electric charge).
The first problem is solved by increasing density. The more nuclei you have in the same volume, the higher the likelihood of close contact. This is where pressure comes in - that's how you get a higher density. Stars are made of plasma, and plasma is easily compressible, similar to a gas, so as pressure increases, so does density. How compressed is it? Well, the Sun's core, where the fusion reactions are actually happening, contains 34% of the Sun's mass, in only 0.8% of the Sun's volume. In the centre, the density is around 150 times the density of liquid water. The pressure is about 100 000 times the pressure in the Earth's core, and about 100 000 000 times the pressure of the water on the bottom of the Mariana trench.
The following is multiple choice question (with options) to answer.
Seas are the largest source of fluid on | [
"dry planet",
"wet planet",
"solar planet",
"ice planet"
] | B | oceans contains most of earth 's water |
OpenBookQA | OpenBookQA-2296 | 5,224 views
In a certain town, the probability that it will rain in the afternoon is known to be $0.6$. Moreover, meteorological data indicates that if the temperature at noon is less than or equal to $25°C$, the probability that it will rain in the afternoon is $0.4$. The temperature at noon is equally likely to be above $25°C$, or at/below $25°C$. What is the probability that it will rain in the afternoon on a day when the temperature at noon is above $25°C$?
1. $0.4$
2. $0.6$
3. $0.8$
4. $0.9$
Answer is C) $0.8$
$P$(rain in afternoon) $= 0.5\times P($rain when temp $\leq 25) + 0.5 \times P($ rain when temp $> 25 )$
$0.6 = 0.5\times 0.4 + 0.5\times P($ rain when temp $> 25 )$
so,
$P$( rain when temp $> 25$ ) $= 0.8$
This is a question of Total Probability where after happening on one event E1, the probability of another event E2 happening or not happening is added together to get the probability of happening of Event E2.
Given P(Rain in noon) =0.6 (This is total probability given).
"The temperature at noon is equally likely to be above 25°C, or at/below 25°C."
means P(Temp less than or 25) = P(Temp >25) =0.5
P(Rain in noon) = P(Temp $\leq$ 25) * P(Rain | Temp $\leq$ 25) + P(Temp $>$ 25) * P(Rain| Temp $>$ 25)
0.6= (0.5*0.4) + (0.5*X)
X=0.8 Ans (C)
The following is multiple choice question (with options) to answer.
Where is it most likely to rain? | [
"in the state of New Mexico",
"at a seaside resort",
"at a cabin in the desert",
"on one's wedding day"
] | B | as air pressure decreases , the chance of rain will increase |
OpenBookQA | OpenBookQA-2297 | special-relativity, spacetime, coordinate-systems, inertial-frames, geometry
Title: The effects of Lorentz transformation on shape Imagine a solid 3D cube. Now imagine that this cube is traveling close to the speed of light. To what degree will the spatial geometric properties of this object (or in general of any 3D object) change (as predicted by the Lorentz transformations)?
I assume that despite the changes to shape, some fundamental geometric features of 3D objects are preserved no matter the frame of reference. I assume that a cube will preserve some of its fundamental geometry Namely, a cube undergoing Lorentz contraction will not become a torus or vice-versa. (I might be wrong about this) But what is the formal limit to these changes? Will the affine structure of a 3D object undergoing Lorentz contractions change or would its topology also change? The Lorentz contraction is a statement about how a given object, which should be regarded as a region of spacetime (not just space since the object continues to exist over time), will be determined to have different spatial dimensions depending on which inertial reference frame is being adopted in order to specify how spacetime is to be divided into "space" and "time".
The above opening statement may seem a bit perplexing if you have only met the Lorentz contraction in its simplest form, but in the following you will see why I have written this somewhat more careful and technical statement.
In the simplest scenario, one considers an object which is itself in internal equilibrium (so not vibrating or sloshing internally) and is moving inertially (not accelerating overall) and without any rotation. In this case the Lorentz contraction is a simple linear "squeeze" in one direction (the direction of motion of the object relative to the observer reporting the contraction). The object is not really being "squeezed" by any force, it is simply that it occupies less of space along one direction than it does to another observer. There is no change in topology.
The following is multiple choice question (with options) to answer.
Which of the following changes shape of an object? | [
"spinning liquid mercury",
"blowing on gases",
"ripping paper",
"cutting water"
] | C | tearing an object changes that object 's shape |
OpenBookQA | OpenBookQA-2298 | electromagnetism
Title: Region of most and least intense magnetic field
It's a unmagnetized iron screw placed in the north pole of a U shaped magnet. I believe the region of least intense magnetic field is at the far left of the board. From what I understand the screw becomes magnetized and it's south pole is where it's touching the north of the magnetic, is it correct to assume the most intense magnetic field will be where the screw is touching the magnet due to there being direct contact between them?
Consider these images showing the magnetic field lines of a horse-shoe magnet. Magnetic intensity at any point in its field is directly proportional to its magnetic flux.So the region where the field lines are more densely packed have a higher intensity than where the field lines are loosely packed. If possible, draw the field lines for your own case and you will realize where the magnetic intensity is most and least.
The following is multiple choice question (with options) to answer.
Where would you most likely see a powerful electromagnet? | [
"at the gym",
"at the pool",
"at car junkyards",
"at middle school"
] | C | electromagnets can be powered by electricity |
OpenBookQA | OpenBookQA-2299 | thermodynamics, solid-state-physics, electric-current, conductors, metals
Title: Why is the heat flow in metals slower than the current flow? When we apply a voltage across a metallic conductor, the current starts to flow almost instantaneously. But when a temperature difference is established across the same conductor, the flow of heat is much slower. It takes larger time for the heat to reach from one end to the other than the current. Why is this so? The current flows almost instantaneously because it is driven by an electric field which appears across the conductor almost instantaneously (near the speed of light). All electrons in the conductor are set into motion by a chain reaction. Collectively they all move through the conductor at what is called the drift velocity at the same time.
By contrast, heat transfer by conduction requires the transfer of energy by collisions between particles in the material that starts at the high temperature end of the conductor and progresses gradually to the low temperature end of the conductor. In the case of metals, the particles are primarily electrons.
Hope this helps.
The following is multiple choice question (with options) to answer.
Which of the following would slow the flow of electricity? | [
"a metal fork",
"a pencil eraser",
"a paper clip",
"aluminum foil"
] | B | an electrical insulator slows the flow of electricity |
OpenBookQA | OpenBookQA-2300 | thermodynamics, everyday-life
Title: Why do fruits left to dry in the sun feel so much warmer to the touch than other objects outside? I have been putting preserved plums, on a rack, to sun and dry on my balcony. When I take them in at dusk, the plums are noticeably hot to the touch. They feel warmer than the bamboo and metal racks they are on, the cardboard box I put the racks on, the netting I put over the lot, and the air outside. (Note that ambient air temperature doesn't start dropping until well after I have the plums indoors.) The balcony itself, made out of a light-colored concrete-like composite, and the metal railing also feel warm, but not as much as the plums do.
I recall some relevant concepts from physics classes, but I can't tell if I'm taking into account everything at play. Here's what I have so far:
Plums are mostly water, which has a high specific heat (~4 kJ/kg/K) relative to air (~1 kJ/kg/K) and probably the other objects. I'm guessing the balcony also has a higher specific heat than air. Higher specific heat means that by the end of the day, the plums have stored more thermal energy than the cardboard box.
Water and metal are good thermal conductors, so they will feel warmer to my hands than the other objects even if they contain the same energy per unit.
Is there something else in here about the plums converting radiant energy to thermal that the other objects don't, or something about air flow? Is it a sign (which I suppose is not for Physics.SE) of fermentation? You were on track...and then missed the mark.
Higher specific heat means that by the end of the day, the plums have stored more thermal energy than the cardboard box."
Correct. You're on track...
Water and metal are good thermal conductors, so they will feel warmer to my hands than the other objects even if they contain the same energy per unit.
The following is multiple choice question (with options) to answer.
A person may source warmth from | [
"embers",
"flowers",
"rain",
"ice"
] | A | a hot something is a source of heat |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.