Question

A girl of mass 10 kg climbs up a staircase having 7 steps each 10 cm high. Calculate the work done by her

Answer 1

Given:-

• Mass of Girl ,m = 10Kg

• No. of steps = 7

• Height of each steps = 10cm

To Find:-

• Work done by her ,W

Solution:-

As we know that the acceleration due to gravity is 9.8m/s².

Height climbs by girl after 7steps=7×10=70cm

⠀⠀⠀⠀⠀⠀⠀⠀⠀= 70/100 = 0.7m

Here ,the Work Done is equal to the Potential Energy .

• PE = W = mgh

• W = mgh

here,

W is the work done

m is the mass

g is the acceleration due to gravity

h is height

Substitute the value we get

➨ W = 10×9.8×0.7

➨ W = 7 × 9.8

➨ W = 68.6 Joules.

Therefore, the Work Done by the girl is 68.6 Joules.

Answer 2

W = Mgh

=} W = 10×9.8×0.7

=} W = 7 × 9.8

=} W = 68.6 Joules.

Please Follow Me .