A diver (mass 100kg.)drops from a height of 12 meters and reaches the pool below at ground level. 3550 joules of heat energy are generated due to friction. With what speed will the diver hit the water?
m g h = potential energy at top
= 100 * 9.81 * 12 = 11,772 Joules
loses 3550 Joules so
(1/2) (100) v^2 = 11,772 - 3550 = 8222 Joules
v = 12.8 m/s