A uniform 100.0g, one-half-meter stick is suspended by a short chain of negligible mass passing through a small hole at the top end of the stick, and is it hanging vertically. At some point 10.0g piece of gum moving at 2.5m/s in horizontally hits the meter stick at its bottom edge, sticking to it.
A. Explain in one sentence why the linear momentum of the system is not conserved in the collision.
B. Explain one sentence by the angular momentum of the system around the relevant axis of rotation is conserved in a collision.
C. Find the angular velocity of this system just after the collision.