A 0.054-kg pet lab mouse sits on a 0.35-kg air-track cart. The cart is at rest, as is a second cart with a mass of 0.25 kg. The lab mouse now jumps to the second cart. After the jump, the 0.35-kg cart has a speed of v1=0.87m/s
What is the speed v2 of the mouse and the 0.25-kg cart?