posted by Meagan .
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 95 kg. The mass of the rock is 0.34 kg. Initially the wagon is rolling forward at a speed of 0.50 m/s. Then the person throws the rock with a speed of 17 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.
got it already thanks