8.4 Exercise 13

Two objects of equal mass collide. Object A is initially moving in the +x-direction with a speed of 12 m/s, and object B is initially at rest. After the collision, object A is at rest, and object B is moving away with some unknown velocity. There are no external forces acting on the system of two masses. What statement can we make about this collision?

1. Both momentum and kinetic energy are conserved.
2. Momentum is conserved, but kinetic energy is not conserved.
3. Neither momentum nor kinetic energy is conserved.
4. More information is needed in order to determine which is conserved.