Question

please give me the answer

Answer 1

Solution:

_________

Previous level of water = 20m

new level of water = 20 - 5 = 15m

To reach the water level we need rope

Length of rope = 15m (below ground) + 1m 20 cm Wall above ground) + 80cm (distance from wall to the pulley)

⇒ 15m + 1.2m + 0.8m

⇒ 17m

So we need a rope of  17m in length to reach the pulley.