physics
posted by andy .
A 4.85kg box is sliding across the horizontal floor of an elevator. The coefficient of kinetic friction between the box and the floor is 0.440. Determine the kinetic frictional force that acts on the box when the elevator is (a) stationary, (b) accelerating upward with an acceleration whose magnitude is 2.35 m/s2, and (c) accelerating downward with an acceleration whose magnitude is 2.35 m/s2

(1) Calculate the force of the floor on the body in each situation.
(2) Multiply that "floor" force by 0.44 for the friction force.
(3) Divide the friction force by M = 4.85kg for the deceleration rate.