physics
posted by Jen .
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.

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.