Water is slowly coming out from a vertical pipe. As the water descends after coming out, its area of cross section reduces. Explain this on the basis of the equation of continuity.

Let the area of the pipe be and the velocity of water exiting the pipe be . After coming out, let the cross-sectional area be and the velocity be .

Now, as water descends, its velocity increases as gravity acts on it. hence,

Hence, . The cross-section decreases as the water comes out of the pipe.