Question

Water flows at the rate of 1.5 meters per second through a pipe with area of cross section 2.5 cm2 into a rectangular water tank of length 90 cm and breadth 50 cm. Find the rise in water level in the tank after 4 minutes.

Answer 1

Rate of flow of water
= 15m/s
= 150cm/s
Rate of volume of water flown 
= Rate of flow x cross section area
= 150 x 2.5
= 375cm³/s
Total volume of water flow
= Rate of volume of water flown x Time
= 375 x (4 x 60 seconds)
= 90000cm³
Volume of water flown
= Volume of water in the tank
90000 = l x b x h
90000 = 90 x 50 x h
h = 20cm
∴ The rise in the level of water is 20cm.