Question

a pool has a uniform circular cross section of radius 5 m and uniform depth 1.4 m . it is filled by a pipe which delivers water at the rate of 20 l L per sec . calculate , in min the time taken to fill the pool . if the pool is emptied in 42min . by another cylindrical pipe through which water flows at the 2 m per sec , calculate the radius of the pipe in cm

Answer 1

Radius of pool    r = 5m
Height of pool     h = 1.4 m

Thus volume of pool = pi  r^2 * h
                                  = 22/7 * 25 * 1.4
                                  = 110 m^3
1 m^3 = 1000 lit
So                             Volume = 110000 Lit

pool filled in 1 sec   = 20 lit
in time T        =  110000
Thus          T = 110000 / 20
                  T = 55000 Sec
                      = 55000/ 60
                      = 916 min