A uniform rod has a mass 2m and a length l, and it can spin freely in a horizontal plane about a pivot point O at the center of the rod. A piece of clay with mass m and velocity v hits
one end of the rod, and causes the rod-clay system to spin.
After the collisions the rod and clay system
has an angular velocity omega about the pivot.
I) total mechanical energy
II) total linear momentum
III) total angular momentum with respect to pivot point O
IV) total gravitational potential energy
V) total kinetic energy
is/are conserved in this process?
1. III and IV only
2. II and III only - tried, was wrong
3. II, III, IV and V only
4. II, III and IV only
5. II and V only
6. I, II and III only
7. I only
8. None of these
9. III, IV and V only
10. All of these
The Attempt at a Solution
I tried II and III only as a solution, but it was wrong. I'm thinking that mechanical energy, kinetic energy, and gravitational potential energy are not conserved due to the introduction of a piece of clay, but it seems I'm wrong in some area. Can anyone help point me in the right direction?