Water coming out of the mouth of a tap and falling vertically in streamline flow forms a tapering column, i.e., the area of cross-section of the liquid column decreases as it moves down. Which of the following is the most accurate explanation for this ? .

Water coming out of the mouth of a tap and falling vertically in strea

1.	Water coming out of the mouth of a tap and falling vertically in streamline flow forms a tapering column, i.e., the area of cross-section of the liquid column decreases as it moves down. Which of the following is the most accurate explanation for this ? .
Answer» As the water down, its speed increases and hence its pressure decreases. It is then compressed by the atmosphere. Falling water TRIES to reach a terminal velocity and hence REDUCES the area of cross-section to balance upward and downward forces. The mass of water flowing past any cross-section must remain CONSTANT. Also, water is almost incompressible. Hence, the rate volume flow must remain constant. As this is equal to velocity `xx` area, the area decrease as velocity increases. The SURFACE tension causes the EXPOSED surface area of the liquid to decrease continuosly. Answer :C