Question

Water running in a cylindrical pipe of inner diameter 7 cm is collected at the rate of 190 2.5 m per second find the rate of flow of water in kilometre per hour

Answer 1

Diameter of cylindrical pipe = 7 cm
∴ Radius of cylindrical pipe = 7/ 2
Volume of water flows in 1 min = 192.5 l
∴ Volume of water flows in 1 hour = 192.5 × 60 × 1000 cm^3 ….....(1)
Let l be the distance covered by water in 1 hour
Volume of water that covers the diameter of 1 hour = πr^2 l .....(2)
From (1) and (2)
⇒ πr^2 l = 192.5 × 60 × 1000
⇒ (22/ 7) x (7/2)^2 x l = 192.5 × 60 × 1000
⇒ l = (192.5 × 60 × 1000 x 2 x 2 x 7)/ (22x 7 x 7)
l = 300000 cm
l = 3 km
i.e. distance covered by water in 1 hr is 3 km
∴ Rate of flow of water = 3 km/hr.