An incompressible liquid flows through a horizontal tube as shown in the following fig. Then the velocity v of the fluid is
(a) 3.0 m/s (b) 1.5 m/s
(c) 1.0 m/s (d) 2.25 m/s
(c) If the liquid is incompressible then mass of liquid entering through left end, should be equal to mass of liquid coming out from the right end.