Your family is moving to a new apartment. While lifting a box 1.5 m straight up to put it on a truck, you exert an upward force 300 N for 1.0 s. How much power is required to do this?

Question

Your family is moving to a new apartment. While lifting a box 1.5 m straight up to put it on a truck, you exert an upward force 300 N for 1.0 s. How much power is required to do this?
 Do I work this like this or?
P = W/t 
W= 300N. 1.5m*cos(0)=400J

oobleck · Answer

P = work/time = F*d/t = 300N * 1.5m / 1.0s = 450J/1s = 450W The cos(0) is correct, but generally omitted if the force is exerted straight up.