A -kg box is being lifted by means of a light rope that is threaded through a single, light, frictionless pulley that is attached to the ceiling. If the box is being lifted at a constant speed of m/s, what is the power delivered by the person pulling on the rope? If the box is lifted, at constant acceleration, from rest on the floor to a height of m above the floor in s, what average power is delivered by the person pulling on the rope?