Recent content by cowpuppy

Shear stresses in shrink fit assembly? I'm trying to figure out what shear stresses there would be from a shrink fit assembly, if any. You have a cylindrical solid shaft and a cylindrical hub, where the shaft diameter is greater than the hub's hole diameter. The shaft cooled and thus shrunk and...

I don't think that's the reason. Just because it is a solid doesn't mean the density doesn't change. And in the case of a block of material with no holes, if you were to heat it, it would expand in all unrestricted directions, and the volume (therefore, density, since mass is the same) would...

Why?

Say you had a material with a hole in it. When you heat this material, it expands. Would the hole then contract, since the material is expanding in all directions? My intuition says yes, but I'm told this is not the case, and I'm not sure about the physics behind it to reason to figure out why.

I'm not quite understanding what I should conclude from this. There is heat transfer independent of the work of the piston? So, Q - W_b = \Delta U Can Q be calculated assuming volume is constant, since the change in internal energy is already accounted for in the work term?

Why is the change in internal energy not equal to the work done? I'm also not sure how I can equate change in temperature to change in internal energy. The only relevant equation that we have covered so far is \Delta U = m C (T_{2} - T_{1}) But in all other cases, either volume or...

Homework Statement A pistol-cylinder device contains 0.8kg of nitrogen initially at 100kPa and 27 degrees C. The nitrogen is compressed in a polytropic process during which PV^1.3 = constant until the volume is reduced by one half. Determine the work done and the heat transfer for this...

What happens when two masses touch? I mean, really touch. When I touch something, I know that the atoms in my hand are separated by some distance from the object I am touching, due to mutual repulsion by the electromagnetic force. So, if two charge-less masses were to collide with each...