A 45 kg student runs up a flight of stairs that are 3.2 m high in 2 seconds. How much power did the student use during this time?
706 W
288 W
72 W
7.0 W
Power=Work/time. In this case Work=increase in potential energy. Supposing he was initially on the floor, W=mgh=45*9.8*3.2=1411.2 J. Therefore Power=1411.2/2=705.6≈706 W.
