Inelastic Collision Problem. Help

[blue_bee29]

Homework Statement

A cart of mass 1.2 kg that is moving to the right qt 3m/s collides on a block of wood of mass 0.8 kg that is lying at rest on top of a frictionless table. if the collision is inelastic, find the velocity of the composite body.

Homework Equations

The Attempt at a Solution

 

[radou]

Well, since you're mentioning a composite body and it's velocity, we're talking about a perfectly inelastic collision. Which equation could you apply to solve the problem, i.e. what is conserved here in your situation?