We have two carts moving towards each other at different speeds andstick together after colliding. Use the information to calculate the velocity of the two carts after the collision. Remember that the carts are moving in opposite directions before the collision and ignore friction.

Mass 1: .51 kg
Velocity 1: 1.1 m/s
Mass 2: .50 kg
Velocity 2: .7 m/s
Velocity final: ?

If someone can help me get started I think I should be able to finish up. I just don't know how to begin.

2 answers

Actually I think I solved this one. I set P= M1V1-M2V2 and then used the equation Pfinal = (M1+M2)•V final and then solved. Is that right?
That is correct. This is a case of inelastic collision where linear momentum is conserved because there is no external force. So, Pi = Pf