A cave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. The lift is performed in three stages, each requiring a vertical distance of 10.0m:
a) the initially stationary spelunker is accelerated to a speed of 5.00 m/s;
b) he is then lifted at the constant speed of 5.00 m/s;
c) finally he is decelerated to zero speed. How much work is done on the 80.0 kg rescuee by the force lifting him during each stage?