Question

A girl lifts up a mass of 25 kg though a stair of 60 steps ,each of height 15 cm. Calculate the work she does.

Answer 1

Answer:

mass= 25 kg

WORK= mgh

Consider g as 9.8

H=15 cm converting them to meter

0.15m

M*G*H= 25*9.8*0.15

=36.75 J

Consider g as 10 your answer is

m*g*h=25*10*0.15=37.5J

HOPE IT HELPS!!!

Answer 2

Answer:

• The work done (W) by the girl is 2250 Joules

Given:

1. Mass of girl (M) = 25 Kg
2. No. of steps (n) = 60 steps.
3. Height of each stair (s) = 15 cm = 15 × 10⁻² m

Explanation:

$\rule{300}{1.5}$

Firstly we need to find vertical Height to which Girl rises.

For that,

⇒ H = n × s

Where,

• H Denotes the Vertical height.
• n Denotes Number of steps.
• s Denotes Height of each step

Now,

⇒ H = n × s

Substituting the values,

⇒ H = 60 × 15 × 10⁻²

⇒ H = 900 × 10⁻²

⇒ H = 9

⇒ H = 9 meters.

∴ We got the vertical height to which the girl rises.

$\rule{300}{1.5}$

$\rule{300}{1.5}$

From Work done formula we know,

⇒ W = M g H

Where,

• W Denotes Work Done.
• M Denotes Mass.
• g Denotes Acceleration due to gravity.
• H Denotes the vertical height.

Now,

⇒ W = M g H

Substituting the values,

⇒ W = 25 kg × 10 m/s² × 9 m

⇒ W = 25 × 10 × 9

⇒ W = 250 × 9

⇒ W = 2250

⇒ W = 2250 Joules.

∴ The work done (W) by the girl is 2250 Joules.

$\rule{300}{1.5}$