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/sci/ - Science & Math

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7921841 No.7921841[DELETED]  [Reply] [Original]

When I apply heat to a metal ring, will the hole in the middle shrink or expand?

>> No.7921875

expand

>> No.7921877

shrink

>> No.7921880

>>7921841
it will detonate into a runaway nuclear reaction

>> No.7921885

>>7921841
I could pretend to be blind and answer your question but that'd be too easy.

Your question is wrong because the hole of a ring is not a thing. It is not a thing that shrinks or expands because it simply is the lack of material.

>> No.7921893

>>7921885
We're talking about the space in between the ring, which is indeed a real thing that exists.

>> No.7921918

It depends on how fast the length of the ring grows compared to its width. However, if the width did grow so fast as to encroach on the hole, it might have difficulty for difference in tension between inside and outside. pi/r something something

>> No.7921964

>>7921841
shrink because the metal expands in all directions

>> No.7921976

Pretty sure it would stay the same. Assuming it's being heated uniformly, it would press from all directions towards the center, cancelling out the force and necessitating the expansion of the outer edge of the ring.

Another question: if you heat an oval ring, will it become more circular? What about a non-uniform band?

>> No.7921983

>>7921976
>canceling out the force
what? You're thinking in 2D, remember that the metal can also expand sideways, as in perpendicular to the ring

>> No.7922009

>>7921983
Ah, you're right, it may expand upwards or downwards relative to the ring, but I still believe that the uniform pressure towards the center would prevent the hole from changing size and instead make the outer diameter greater. Path of least resistance sort of thing.

>> No.7922013

>>7922009
I wonder if there are any videos of this stuff

>> No.7922017
File: 269 KB, 1589x1363, image.jpg [View same] [iqdb] [saucenao] [google]
7922017

>> No.7922018

>>7922017
so it looks like >>7921976 was right after all. Interesting

>> No.7922072

>>7922018

That's not what it shows. The hole gets larger in that image.

>> No.7922078

>>7922072
If you had a ring stuck on your finger, heating it up would make it easier to remove? (ignoring pain)

>> No.7922081

It expands. trust me, i are a engineer. Think: The bushes and bearings in your car etc. A bearing is HEATED to expand. For a BUSH the main casting is heated or bush is FROZEN.

>> No.7922083

>>7922009
>I still believe that the uniform pressure towards the center would prevent the hole from changing size and instead make the outer diameter greater

Well, that's not correct, which is pretty easy to show experimentally (eg running the lid if a jar under hot vs cold water).

Think of it this way - if the hole got smaller, the atoms of the inner edge would have to get closer together, since it's a solid object and their relative positions are fixed.

>> No.7922095

https://www.youtube.com/watch?v=UJfY7ZzTvf4
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