1. The problem statement, all variables and given/known data 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. a) If the box is being lifted at a constant speed of 2.0 m/s, what is the power delivered by the person pulling on the rope? b) If the box is lifted, at constant acceleration, from rest on the floor to a height of 1.5m above the floor in 0.42 s, what average power is delivered by the person pulling on the rope? 2. Relevant equations k = 1/2 m v^2 (velocity vector) d = initial velocity(t) + 1/2at^2 v = initial velocity + at 3. The attempt at a solution My answer for a is 15 Joules. I basically just plugged in the numbers for this one, since we are only going in the y direction I didn't bother writing ( 0i + 2.0j) k = (1/2)(7.5)(2.0)^2 = 15 Joules My answer for b is 190 Joules. For this one I found the acceleration and then the velocity and plugged in those numbers. 1.5 = 1/2a(0.42)^2 a = 17 m/s^2 v = 17(0.42) = 7.1 m/s k = 1/2 (17) (7.1)^2 = 190 Joules Can anyone tell me if these answers are correct?