Question

Water runs into a tank of diameter 4 and height 5 metres . Acircular holr ehose diameter is 4 cm at 1/10 m per second. Find the time requirrd for tge tabk to be filled up.

Answer 1

Let  tank  filled   x sec.

Water   is   flowing   at   the   rate  of   1/10  m/s.

Length of the water coloumn in x sec = x/10  m      

The water column forms a cylinder of of radius

r = 2 cm = 0.02 m and h (length) = x/10 m

Volume of water that flows in the tank in x sec =  r2 h = (22/7 * 0.02 * 0.02 * x/10 ) m3

Therefore

    Volume of tank = Volume of the water flows in the cistern in x hours

22/7 * 2 * 2 * 5 = 22/7 * 0.02 *0.02 * x/10

                           = 500000 sec

                           = 500000 / 60 * 60 = 138.9 or 139 hours