I have a quick physics 12 problem A helicopter of 5500 kg starting from rest reaches a height of 5500 m with a velocity of 210 m/s. If this happens in 900 seconds, what is the Power? i'm not sure how to do this one, i used P = W/t and solved for work being Ef - Ei. but is there no initial energy? so is it just P = Ek + Ep (both final)/t to solve? thanks!