A wagon is rolling forward on level ground. Friction is negligible. The person sitting in the wagon is holding a rock. The total mass of the wagon, rider, and rock is 94 kg. The mass of the rock is 0.27 kg. Initially the wagon is rolling forward at a speed of 0.49 m/s. Then the person throws the rock with a speed of 15 m/s. Both speeds are relative to the ground. Find the speed of the wagon after the rock is thrown (a) directly forward in one case and (b) directly backward in another.

1 answer

the momentum of the system stays constant ___ 94 * .49

forward throw
(94 - .27)x + (.27 * 15) = 94 * .49

backward throw
(94 - .27)x - (.27 * 15) = 94 * .49