The uniform 60-kg crate c rests uniformly on a 10-kg dolly d. if the front casters of the dolly at a are locked to prevent rolling while the casters at b are free to roll, determine the maximum force p that may be applied without causing motion of the crate. the coefficient of static friction between the casters and the floor is μf=0.35 and between the dolly and the crate, μd=0.5.