A 51-kg woman runs up a vertical flight of stairs in 5.0 s. Her net upward displacement is 5.0 m. Approximately, what average power did the woman exert while she was running?

The average power the woman exerts is 0.5 kW

Explanation:

We note that power, P = The rate at which work is done = Work/Time

Work = Energy

The total work done is the potential energy gained which is the energy due to vertical displacement

Given that the vertical displacement = 5.0 m, we have

Total work done = Potential energy gained = Mass, m × Acceleration due to gravity, g × Vertical height, h

m = 51 kg

g = Constant = 9.81 m/s²

h = 5.0 m

Also, time, t = 5.0 s

Total work done = 51 kg × 9.81 m/s²× 5 m = 2501.55 kg·m²/s² = 2501.55 J

P = 2501.55 J/(5 s) = 500.31 J/s = 500.31 W ≈ 500 W = 0.5 kW.

the answer is b, have negligible mass