A 49.4 kg swimmer is standing on a stationary 214 kg floating raft. The swimmer then runs off the raft horizontally with a velocity of +3.60 m/s relative to the shore. Calculate the magnitude of the recoil velocity that the raft would have if there were no resistance due to the water.

Answer 1

Use the fact that total momentum remains zero.

49.4 * 3.60 + 214 * Vraft = 0

Solve for Vraft

The negative sign will mean it goes backwards.