Question

500 persons are taking a dip into a cuboidal pond which is 80 m long and 50 m broad. What is the rise of water level in the pond, if the average displacement of the water by a person is 0.04m³?

Answer 1

According to the question,

Average displacement by a person = 0.04 m³

Average displacement by 500 persons = 500 × 0.04 = 20 m³

Hence, the volume of water raised in pond = 20 m³

It is also given that,

Length of pond, l = 80 m

Breadth of pond, b = 50 m

Height = h

Volume of water raised in pond = 80(50)(h)

20 m³ = 4000h

h = 0.005 m = 0.5 cm

Therefore, raise in the height of water = 0.5 cm.