You and a friend are in a small boat on Table Rock Lake. When the boat is not moving with respect to the water, you and your friend exchange position in the boat. The seats are 1.5 meters apart. The boat moves 25cm relative to the water as a result of you changing position in the boat. Determine the mass of your friend, if your mass is 80 kg and the mass of the boat is 30 kg. Assume that you are heavier than your friend.