Question

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 95.5 kg. the mass of the rock is 0.290 kg. initially the wagon is rolling forward at a speed of 0.510 m/s. then the person throws the rock with a speed of 17.5 m/s. both speeds are relative to the ground. find the speed of the wagon after the rock is thrown directly forward.

Answer 1

use the equation mv+mv=mv+mv

95.5(.51)= 95.2(X)+ 17.5(.290)

Now solve for X and that should be your answer

OR

you know that if you throw the rock forward then the the same amount of force is applied backwards onto the person throwing the rock so if the force applied to the rock is mass times velocity then find the force for the cart and subtract the carts force forward by the force the rock exerts backwards.