Question

a 90 kg firefighter needs to climb the stairs of a 20-m-tall building while carrying a 40 kg backpack filled with gear. how much power does the firefighter need to reach the top in 55 s?

Answer 1

`\huge\boxed{\sf Power = 1274\ W}`

Step-by-step explanation:

Given data:

Total mass = m = 90 kg + 40 kg = 130 kg

Height = h = 20 m

Acceleration due to gravity = g = 9.8 m/s²

Time = t = 55 s

Required:

Power = P = ?

Formula:

`\displaystyle P=(Work)/(Time)`

Solution:

Here, the work is done in the form of potential energy.

So,

Work = P.E

As we know,

P.E = mgh

P.E = (130)(9.8)(20)

P.E = 25480 J

So,

Power = P.E / time

Power = 25480 / 20

Power = 1274 W

`\rule[225]{225}{2}`