500 persons have to dip in a rectangular tank which is 80 m long and 50 m broad. What is the rise in the level of water in the tank, if the average displacement of water by a person is 0.04 m3?
Length of rectangular tank, l = 80m
Breadth, b = 50m
Total displacement of water in rectangular tank by 500 persons = 500 × 0.04 m3 = 20m3 -----(i)
Let depth of the rectangular tank be h
Volume of rectangular tank = lbh
= 80 × 50 × h m3 -----------(ii)
Equating (i) and (ii), we get
20 = 80 × 50 × h
⇒ h = 0.005m = 0.5cm
∴ rise in level of water due to angular displacement = 0.5cm