Question

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?

Answer 1

Answer:

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.