1. The problem statement, all variables and given/known data A 7-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 lifted, at constant acceleration, from rest on the floor to a height of 1.5 m above the floor in 0.42 s, what average power is delivered by the person pulling on the rope? 2. Relevant equations (1) d = V0t + 0.5at2 (2) F=ma (3) W = Fd (4) P = W/Δt 3. The attempt at a solution (1) a = 17m/sec2 (2) F = 7*17 F = 119 (3) W = 119*1.5 W = 178.5 (4) P = 178.5/0.42 P = 425 Here's the thing, that answer agrees with the equation in the solution manual, but not on my homework. I'm reworking an old problem and I got it correct the first time around and can't figure out how I arrived at the answer, which is 0.67kW.