Question

water level in a well was 20 m below ground level. The wall of the well is 1m 20 cm high and a pulley is fixed at a height of 80 cm from the wall. Raghav wants to draw water from the well. The minimum length of the rope that he can use is

Answer 1

As water level in a well was 20m below ground level.
So water is at 20m below the ground.

The wall of the well is 1m 20cm high a pulley is fixed at a height of 80cm from the wall.
Wall of the well is always above the ground moreover pulley is fixed at a height of 80cm from the wall.
So height at which pully is fixed from the ground = 1 m 20 cm + 80 cm = 2 m

To draw water from the well we need to have one end of the rope touching the water and other end touching the pully.

Minimum length of the rope required to draw water from the well
= 20 m + 2 m
= 22 m

Answer 2

23 mtrs. 20+1.2+0.8+0.8+0.2(for holding it properly.)