# Tag Info

### Shouldn't length contraction cause friction under certain circumstances?

I don't think it's all that complicated. Let’s assume that in your train problem there is a rack and pinion action between the train wheels and the track instead of friction. Assume that the speeding ...

### How do we justify that potential energy in a spring is Galilean invariant (to the extent that Newtonian mechanics holds)?

From this I surmise that the elastic potential energy of a compressed spring can be ultimately reduced down to electromagnetic energy. Well, yes, but you have to use the quantum mechanical rules of ...
• 64.2k
1 vote

• 400
1 vote

### Confusion in Derivation of Excess Pressure in a Cylindrical Drop

That's a good start, however there are some subtleties behind treating surface tension as a force. Indeed, there are some classic problematic cases that are often overlooked at first. The best way to ...
• 1,145
1 vote

### Shouldn't length contraction cause friction under certain circumstances?

This question is complicated by using accelerated frames (not just one but two differently accelerated frames, one for the front and one for the back of the train) plus the unintuitive weirdness that ...
• 8,068
1 vote
Accepted

### Calculating bulk modulus from interatomic potential on cubic lattice

A little bit of pedantry first: NaCl has a face-centered cubic lattice structure with 2 atoms in the basis (1 Na and 1 Cl), which looks like a simple cubic structure only if we ignore that there are ...
• 9,877
1 vote

### What is an "As-grown crystal"?

Jon Custer's comment is correct. As-grown means the crystals were grown according to a specific recipe, and then were not modified further. Examples of not as-grown would be if you annealed the ...
• 660

Only top scored, non community-wiki answers of a minimum length are eligible