A man brings to work a 5.7 kilogram box of books. By the time he reaches the ramp outside of his office, he attaches a (mass less) rope to the box and drags it up the incline.
a) If he pulls at the 22.62o angle and the coefficient of static friction between the ramp and the box is .42, determine what is the minimum force does the man must apply in order to make the box slide?
b) After pulling long enough to get the box going 3.4 m/s, he lets go of the rope. If the coefficient of kinetic friction between the box and the ramp is .2, obtain how long does it take the box to stop?