A person of 50 kg runs up the stairs 10 meters in height in a time span of 2 minutes. Here, the acceleration due to gravity ‘g’ is 10 m/s2. Determine the power.

Answer:

Known:

Mass ‘m’ = 50 kg

Height ‘h’ = 10 meters

Acceleration due to gravity ‘g’ = 10 m/s2

Time interval ‘t’ = 2 minutes = 2 X 60 seconds = 120 seconds

Wanted: Power ‘P’

Solution:

Formula of Power:

P = W/t

P = power,

W = work, and t = time

Formula of Work:

W  = mgh

W = work,

F = force,

w = weight,

h = height,

d = displacement,

m = mass,

g = acceleration due to gravity

W = mgh = 50 X 10 X 10 = 5000 Joule.

P = W/t = 5000/120 = 41.7 Joule per second.