Question

A man of mass 60 kg runs up a flight of 30 steps in 40 seconds. If each step is 20 cm high , calculate his power.

Answer 1

Given,
mass=60 kg
time=40 seconds
height=20 cm.

Since,
Workdone= mgh

So,
Work done=60.10.20.30 (since,gravity g=10 and he climbed 30 steps)
work done =360000 Joule

now,
P=W/t
P=360000/40
P=9000 Watt.@n$

Answer 2

Given info :

mass = 60 kg

number of steps = 30

height of each step = 20 cm

total height = 20 cm × 30

                   = 600 cm

                   = 6 m

Now work = potential energy

= > work = mgh

g = 10 m/s²

W = 60 × 6 × 10

= W = 360 × 10

= W = 3600

Now power = work/time

W = 3600 J

T = 40 s

P = W/T

= P = 3600 J / 40 s

= P = 90 W

ANSWER:

90 W is the power