A 3,0kg cart moving East with a speed of 1.0ms^-1 collides head-on with a 5.0 kg cart that is initially moving West with a speed of 2.0 m.s^-1. After the collision, then 3.0 kg cart is moving to the left with a speed of 1.0 m.s^-1. IGNORE THE FRICTION, WHAT IS FINAL VELOCITY OF 5.0KG CART?

1 answer

initial momentum east
= 3 * 1 - 5 * 2 = -7
so final momentum east = -7

I guess left is west, negative
-7 = 3 * -1 + 5 * u

5 u = -4

u = 4/5 west