Interesting Inelastic Collision

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
1 replies · 1K views
stanli121
Messages
11
Reaction score
0

Homework Statement


Consider a translating and rotating rigid disk. As it movies, it just tips the top of a rod that is initially at rest. The puck sticks to the rod, forming a rigid body that looks like a
popsicle that after the collision moves on as one rigid body. I did the calculations to show that KE is not conserved but I'm now wondering how KE is not conserved if the contact point of the disk has zero relative velocity with respect to the rod?

Homework Equations





The Attempt at a Solution


Thus far, I am thinking that there is some work done by friction at the mutual contact patch that allows the new rigid body to rotate in such as way as to conserve angular and linear momentum. There is no pivot through the rod so that does not exert a force/torque. Something like 'the rod bends' or 'the disk deforms' seems less than satisfactory. Any ideas as to explain the loss in KE would be much appreciated.
 
on Phys.org