Question

A 0.054-kg pet lab mouse sits on a 0.35-kg air-track cart, as shown in (Figure 1) . 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=0.80m/s.



What is the speed v2 of the mouse and the0.25-kg cart?

Answer 1

well, the initial momentum was zero so the final momentum must be zero.
I assume the first cart goes back and the mouse and cart two go forward
so
0 = -.35*.8 +(.054+.25)V2
.28 = .304 V2