on a windy day, a person on a cart (combined mass m of 70kg) begins at the top of a hill 10m hihg traveling at 3m/s, and coasts to the bottom along a frictionless surface route that is 60 m long, arriving ther egoing 12 m/s. It then encounters a long rough surface with uk=.2 and eventually stops.
a) Find the work done and the direction of the air friction from the top to the bottom of the hill.
b) At what distance from the bottom of the hill did the car stop?