A 66-kg woman runs up a flight of stairs having a rise of 4.0 m in a time of 4.2 s.What average power did she supply?
A) 380 W
B) 560 W
C) 620 W
D) 670 W

Question

Quizplus · Accepted Answer

First, we need to calculate the gravitational potential energy that the woman gained, which is given by mgh, where m is the mass of the woman, g is the acceleration due to gravity (9.8 m/s^2), and h is the height of the stairs. So, the potential energy gained is:
mgh = (66 kg)(9.8 m/s^2)(4.0 m) = 2587.2 J

Next, we can calculate the average power that the woman supplied using the formula:
P = E/t
where P is power, E is energy, and t is time. So, the average power supplied is:
P = 2587.2 J / 4.2 s = 616.57 W

Therefore, the best choice is C, which is closest to our calculated value of 616.57 W.

A 66-Kg Woman Runs Up a Flight of Stairs Having