Question

A man of 25 Kg weight climbs 25 stairs 3
in 20 seconds. If the height of each stair
is 40 cm, find the power. (g=10m/s^2)​

Answer 1

Answer:

125W

Explanation:

power = work done / time

Work done = energy = force x distance

force is measured in Newtons so is weight

weight = mass x g

weight = 25 x 10 = 250 as he weighs 25kg

distance = 25 x 40 ( as each stair is 40cm and there are 25 stairs) = 1000cm

100cm = 10m

work done = 250 x 10 = 2500J (joules)

power = 2500 / 20

power = 125W (watts)

Answer 2

The power of the boy to go up the stairs is 122.5 W

Given:

Mass of the boy = 25 kg

Total number of staircase = 25 stairs

Height of each step = 40 cm

Step-by-step explanation:

Height of the total staircase = 25 × 40/100 = 25 × 0.4

Height of the total staircase = 10 m

Weight of the boy = mg = 25 × 9.8

Weight of the boy = 245 N

Power of the boy = (Work done)/(Total time taken)

Power of the boy = (mgh)/t = (245 × 10)/20

∴ Power of the boy = 122.5 W