A canoeist pitches a 0.145 kg baseball at 21 m/s to a friend in another canoe. Both canoes are initially at rest, and the mass of each canoe including passenger is 120 kg. How fast do the canoes move apart after the second canoeist catches the ball?

Question

noelgreco · Answer

The problem with this question is that there is friction between the canoes and the water.

It is, however, a momentum problem.  The change in momentum is the same (but in an opposite direction) for each canoe system.