Ricardo, of mass 82 kg, and Carmelita, who is lighter, are enjoying Lake Merced at dusk in a 38 kg canoe. When the canoe is at rest in the placid water, they exchange seats, which are 3.1 m apart and symmetrically located with respect to the canoe's center. Ricardo notices that the canoe moves 58.4 cm horizontally relative to a pier post during the exchange and calculates Carmelita's mass. What is it? Thankz to any one who can show how to solve this really appriciate it.