A person runs up a long flight of stairs in 10 seconds.If the person's weight is 600 N and the vertical height of the stairs is 20 meters,the person's power output is
A)0.
B)3 W.
C)30 W.
D)1,200 W.
E)12,000 W.

Question

Quizplus · Accepted Answer

Power output, P = work done/time interval

Work done = force x distance (in the direction of force)

In this case, the force is the weight of the person and the distance is the vertical height of the stairs. So,

Work done = 600 N x 20 m = 12,000 J

Time interval = 10 s

Thus,

Power output = 12,000 J/10 s = 1,200 W

A Person Runs Up a Long Flight of Stairs in 10