# Homework Help: Conservation of Momentum: Pulley System

1. Nov 4, 2016

### Watney

1. The problem statement, all variables and given/known data
Block A (of mass MA) rests on a frictionless horizontal table. It is connected via a light string to block B (of mass MB) hanging over the edge of the table. The pulley itself, a solid disc, has non-negligible mass MC. The light string does not slip over the pulley.
What is the magnitude of the linear acceleration of the system?

Edit: Messed up with the title! This problem is in the chapter of Conservation of Momentum in my book but I actually didn't use it for this problem.
2. Relevant equations
Στ=Iα
α=a/r
Moment of Inertia of a disk = 1/2mr^2

3. The attempt at a solution
So here's my attempt but I'm not sure where I'm messing up.

2. Nov 4, 2016

### Vibhor

Why do you think you are messing up somewhere ?

3. Nov 4, 2016

### Watney

When I enter my answer into my online hw answer checker, it says it's wrong. I'll have to ask my professor if maybe there's a mistake with his website cause sometimes he messes up!
Thanks though!

4. Nov 4, 2016

### TomHart

I don't know where you're messing up. I didn't see anything wrong.

5. Nov 4, 2016

### TomHart

That is probably what happened. I went through the problem twice and got the same result both times.

Acknowledging @Vibhor who answered before me. I didn't see it until after I posted.