Water is flowing at the rate of 15 km per hour though a pipe of diameter 14 cm into a rectangular which is 50 m long and 44 m wide. Find the time in which the level of water in the tank will rise by 21 cm.

Explanation

Length of the tank = 50 m.
Width of the tank = 44 m.
Desired rise in level = 21 cm `= 21/100 m.`
Desired volume of water in the tank
`=(50xx44xx21/100)m^(3)=462m^(3)`
`"Radius of the pipe, r = 7 "cm=7/100m`.
Length of water flowing in 1 hour, h = 15 km = 15000 m.
Volume of water flowing from the pipe in 1 hour
`pir^(2)h=(22/7xx7/100xx7/100xx15000)m^(3)=231 m^(3)`.
`:." required time"=("desired volume")/("volume of water flown in 1 hour")`
`=(462/231)"hours= 2 hours"`.