Answer to Question #80786 in Physics for kari

Question

A toy cart with mass 0.35 kg is moving to the right (positive direction) with a velocity of +0.25 m/s. It collides with a much bigger toy cart (mass of 1.5 kg) and bounces back with a velocity of -0.25 m/s. What is the velocity of the big toy truck after the collision? If you get a negative number, include the minus sign. If you get a positive number, do NOT include the plus sign

Answer 1

From the conservation of momentum:
0.35(0.25)=0.35(-0.25)+1.5v
v=2 0.35(0.25)/1.5=0.12 m/s.