- #1

Bobby345

- 10

- 0

## Homework Statement

A system has a ball and a uniform rod. The rod is rotating about point X on a frictionless table until it strikes the ball. The rod stops and the ball moves away.

Variables:

Rod's mass: m1

Ball's mass: m2

Rod's original angular velocity: ω

Ball's final velocity: v

Rod's moment of inertia about point X: (1/3)(m1L^2)

Length of the rod: L

1. What is the linear momentum of the system before the collision in terms of L, m1, and ω?

2. What is the linear momentum of the system after the collision in terms of L, m1, and ω?

3. Why is the angular momentum about point X conserved during the collision?

4. What makes the linear momentum of the system change during the collision?

## Homework Equations

L=Iω

FΔt=mΔv

## The Attempt at a Solution

I figured out that the speed of the ball after the collision (v) is equal to (m1Lω)/(3m2).

I cannot figure out anything about the linear momentum and conservation of either angular or linear momentum. I suspect that the reason angular momentum is conserved has something to do with torque but I am not positive.