Water flows steadily into a tank through pipes 1 & 2 and discharge at a steady rate out of the tank through pipes 3 & 4. The mean velocity of inflow & outflow in pipes 1,2,3 is 15 m/s and the outflow velocity in pipe 4 varies linearly. Calculate:

a) mass flow rate in pipe 4.

b) average velocity in pipe 4.

c) maximum velocity in pipe 4.