Physics Elena please help!
posted by Anonymous .
A 85.0 kg base runner begins his slide into second base when he is moving at a speed of 2.10 m/s. The coefficient of friction between his clothes and Earth is 0.570. He slides so that his speed is zero just as he reaches the base. (a) How much mechanical energy is lost due to friction acting on the runner? b) how far did he slide?

a
all of it since that was the only force and he stopped.
(1/2) m v^2 = (1/2)(85)(2.1)^2 Joules
b
Force * distance = work done = answer for part a
Force = .57 m g = .57 * 85 * 9.81
so
.57 * 85 * 9.81 * d = answer from part a