Questions related to the Continuum Mechanics Division of Elasticity. The bending of beams, deflection of rods, or in general, applications of Hooke's Law generalized to three dimensions.
Questions tagged [elasticity]
908 questions
133
votes
3 answers
Why is the vibration in my wire acting so oddly?
I was soldering a very thin wire today, and when I had one end firmly soldered, I accidentally bumped the wire diagonally with my tweezers. What I'd expect to happen is that the wire oscillates for a little while in one axis, then stops. However,…
0xDBFB7
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104
votes
12 answers
Why is filling a balloon from your mouth much harder initially?
Why is it that when you first fill up a balloon, it's hard to get air through, but after inflating it a bit, it becomes much easier to further inflate the balloon?
yuritsuki
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100
votes
11 answers
If I pull a metal bar for long enough with a constant small force, will it eventually break?
Let's say I have a strong metal bar. I pull it apart with a very small constant force -- obviously it doesn't break. However, this would disturb the internal configuration. If I let go, then eventually the internal configuration would return to what…
83
votes
6 answers
Why does a rubber band become a lighter color when stretched?
I was stretching a pink colored rubber band, and I noticed that the longer I stretch it, the lighter the pink becomes.
Why does this happen?
wavion
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38
votes
13 answers
If water is nearly as incompressible as ground, why don't divers get injured when they plunge into it?
I have read that water (or any other liquid) cannot be compressed like gases and it is nearly as elastic as solid. So why isn’t the impact of diving into water equivalent to that of diving on hard concrete?
Hitarth Vyas
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36
votes
12 answers
Is it correct to say that it is theoretically impossible for perfect rigid bodies to exist?
If perfect rigid bodies were to exist, then consider a scenario in which two rigid bodies of equal masses moving with velocities of equal magnitude but opposite in direction colliding against one another. During the collision, the velocities of both…
Mathew_
- 548
35
votes
3 answers
Clarifying the actual definition of elasticity. Is steel really more elastic than rubber?
Yes, I know it's steel. It's everywhere on the web and I did google. But I seek enlightenment.
My physics textbook defines elasticity as:
Property by virtue of which a material regains its shape.
Or, the ability of material to resist change in…
sarthak-ag
- 551
32
votes
7 answers
Why can you hammer a hole into an underwater ceramic cup?
Hammering a nail into a ceramic cup causes it to shatter when dry but not when submerged in water. Is there an intuitive explanation for this? And does it have anything to do with the Rehbinder effect?
Image taken from this video. A ton of similar…
AlphaLife
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29
votes
2 answers
Why do my experimental data for Hooke’s law not match the expected data?
As we all know, force applied to a spring is directly proportional to the extension of spring as shown below:
However, my experimental results for a simple spring from a school laboratory don't match this behaviour:
Why is this happening? I don't…
anon
23
votes
2 answers
How does a twisted piece of string/yarn wind back on itself? What kinds of forces are responsible for this?
I do a lot of fibrework (carding wool, spinning yarn, weaving, etc.) and I've noticed a funny behaviour that anything long and flexible, which can withstand significant torque exhibits. If I take a piece of yarn and begin to twist it, it remains…
Nicholas
- 133
22
votes
8 answers
What happens if a slow train hits you?
It's funny, I used to wonder this at school many years ago. For the purposes of discussion, imagine there is a big (very massive) cube that slides towards you as you're sitting on the floor. It doesn't move fast, perhaps (say) walking pace. Would it…
22
votes
4 answers
Why is the stress on a body not a vector?
In my textbook, Physics, Part II—Textbook for Class XI, there's a line which talks about why stress is not a vector:
Stress is not a vector quantity since, unlike a force, stress cannot be assigned a specific direction. Force acting on the portion…
archie
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22
votes
1 answer
Why does a flat sheet roll back into a cylinder when having rolled it once?
For example, if you were to roll a piece of paper into the shape of a hollow cylinder and then try to return the paper to its original, flat shape, it would naturally roll to the cylinder when you let go. Why would an originally flat surface, when…
20
votes
5 answers
Why can one bend glass fiber?
Why can one bend glass fibers without breaking it, whereas glasses one comes across in real life is usually solid?
Is there also a good high-school level explanation of this?
student
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18
votes
2 answers
Can Hooke's law be derived?
Can we derive Hooke's law from the theory of elasticity? I know it is not a fundamental law and therefore can be derived from more basic considerations.
Solidification
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