posted by Ryan .
A 7.5-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 2.0m/s, what is the power delivered by the person pulling on the ropre? If the box lifted at constant acceleration from rest on the floor to a height of 1.5m above the floor in 0.42s what average power is delivered by the person pulling the rope?
power= force*distance/time= mg*velocity
If being accelerated, then force=mg+ma