# Homework Help: Particle collides totally inelastically with a vertical free rod

1. Jun 11, 2013

### rbwang1225

1. The problem statement, all variables and given/known data
A particle of mass M moving on a frictionless surface with velocity $V_0$ collides totally inelastically with an uniform vertical rod of mass M and length L. After immediately the collision, what is the center-of-mass velocity, the moment of inertia about the center-of-mass, and the angular speed of the system.

2. Relevant equations
conservation of momentum and conservation of angular momentum
moment of inertia

3. The attempt at a solution
I am wondering what point does the particle+rod system will rotate about?

2. Jun 11, 2013

### darkxponent

First form the two equations. Conservation of linear and Conservation of angular momentum. As there is no external force and Torque.

3. Jun 11, 2013

### Redbelly98

Staff Emeritus
The problem statement mentions "the moment of inertia about the center-of-mass", so that is a pretty good clue.