Question

The surface of water in a water tank on the top of a house is 4 m above the tap level. Find the pressure of water at the tap when the tap is closed. Is it necessary specify that the tap is closed? Take g =10 $m{s}^{-2}$.

Answer 1

(a) Given, h = 4 m

g= 10 $m/s^2$

$\rho ={10}^{3}kg/m^3$

$p=h\rho g=4\times {10}^3\times 10$

= 40,000 $N/m^2$

(b) It is necessary to specify that the tap is closed. Otherwise pressure will gradually decrease, as h decreases the tap is open and the pressure at the tap is atmospheric.