I think you could be nitpicking about the metal question. It depends on the exact shape and size of plate and holes and they might even get smaller first and then bigger.
The trick is to instead imagine the punched out metal discs instead of the holes. When heated, do these discs get bigger or smaller? Bigger, of course. Therefore, the holes that the discs were punched out of must grow larger.
I'm sure there are contrived situations where somehow this doesn't happen, but that goes against the spirit of these quizzes imo.
I think that's backwards, actually. Sure, the round disks would get larger - because the metal expands. The holes are not made of metal, however. By my thinking, the metal surrounding the holes will expand, and having no where else to go (well, there is the z-direction I suppose), it should expand into the holes.
Think of a metal rod. As you heat it, it gets longer as a proportion of it's length and thicker as a proportion of its thickness. If the rod is 100 times as long as it is thick, the increase in length is 100x more than the increase in thickness. Now bend that rod into a circular ring. The same thing should happen. With such a large increase in length and such a small increase in thickness, the inner diameter of the ring must increase. Make a mesh of these and the holes all get bigger. But what about a tiny hole in a large disk? Cut the disk and straighten it into a rod. Will the rod's thickness ever be more than it's length? It can't be, otherwise, it would never reach around to close on itself, therefore, the holes in any disk must get larger with material expansion. The same applies to octagons, squares, triangles, etc.
I also think it depends on how high you heat the metal and for how long, @Moos1005.
Not being a scientist, I’m thinking in terms of my perforated steel pizza-cooking tray. As I cook pizza a maximum temperature of 250 ℃, I wouldn’t expect any change perceptible to the naked eye in the size of the holes. However, should the same tray be heated to a temperature approaching its melting point, I suspect a more marked increase in the size of the holes may occur.
The metal question is correct. Think of it like this: heated metal atoms need more space between them to account for their heat energy. Say 100 atoms ran around the outer perimeter of a small hole. As the metal heats up, the 100 atoms need to be farther apart from the next closest one. Going inwards would push them closer together. They must go outwards to get more space and therefore the hole expands.
When metal pipe is heated up both the ID and OD grow in diameter. The metal expands all the way around the pipe more then the wall thickness grows. Hope this helps.
The mole question is kind of strange. A mole isn't an object, it's a unit of measurement. It would be like asking "how many molecules are in a dozen?" You get what the question is asking, but a dozen doesn't necessarily represent a dozen molecules, and neither does a mole; you'd be better off asking "how many molecules are in 1 dozen/mole of molecules.
Wow. Giving out the award on the second of the month just shows how arbitrary your rewards are. Does anyone vet these proceedings? Do you have any system for actually awarding these prizes? You probably have big corporations influencing your decisions... you know, "Big Nitpick" keeping their most profitable nitpickers adulated. Stop being an industry sycophant and get back to the artistry of the nitpick. I remember when the Malbaby Nitpick Award meant something... before you sold out.
Centrifugal force does not exist. It's your angular momentum that would at some point exceed what the *centripetal* force (gravity) has to be in order to keep you at that orbital radius.
It is an apparent force, and exists as such and can be used in calculations. In the reference frame of a car, you feel apparent wind. I can use that wind in drag calculations even though I know it's an apparent wind and the air isn't moving.
Depends on who you talk to. There's no set scientific definition of what a "continent" is, so different places define it differently. Some consider North and South America to be a single continent, some consider it two. Same with Europe and Asia. Some consider Australia to be a continent, some consider it an island, some consider it both. Some say Oceania is the continent, others say it's just a region that contains the continent of Australia.
The sheet of metal question could be worded better. There are a few exceptions that the holes would get smaller due to negative thermal expansion. The holes in a sheet of pure silicon heated from 20 K to 100 K (yes very cold) would get smaller.
"Take a sheet of metal with holes in it. Heat the metal from 0*C to 500*C. What happens to the holes?"
I think all BigLaing said was that there was room for improvement with the wording of the question. I agree, but I'm also sure you have higher priorities running the site.
wth with Australia suddenly being a continent? In a quiz by Quizmaster? (and I use the word "suddenly" wrongly)
I also wonder why you'd put the option "amplitude" if you're not going to put the correct option "frequency" in that question - it's right, but a bit weird.
What is 2?
A. an odd number
B. a number that when you halve it leaves a whole number with no decimal places
I'm shocked by the dishonesty of many popular music bands. Eagles are humans, not eagles; there isn't a single beetle in the Beatles. But the Chordettes live up to their name: they really are chordates.
I'm sure there are contrived situations where somehow this doesn't happen, but that goes against the spirit of these quizzes imo.
Not being a scientist, I’m thinking in terms of my perforated steel pizza-cooking tray. As I cook pizza a maximum temperature of 250 ℃, I wouldn’t expect any change perceptible to the naked eye in the size of the holes. However, should the same tray be heated to a temperature approaching its melting point, I suspect a more marked increase in the size of the holes may occur.
Our galaxy is not just a spiral galaxy, in fact it is an barred spiral galaxy!
But since barred spiral galaxies are considered to be a sub-type of spiral galaxies, I'll let that pass for now...
"Take a sheet of metal with holes in it. Heat the metal from 0*C to 500*C. What happens to the holes?"
I also wonder why you'd put the option "amplitude" if you're not going to put the correct option "frequency" in that question - it's right, but a bit weird.
What is 2?
A. an odd number
B. a number that when you halve it leaves a whole number with no decimal places