Question

A water tank has a hole 3.0 cm^2 in area located 2.0 m below the water surface. How many kilograms of water emerge from the hole per second?

Answer 1

The velocity of water will be

$$v=\sqrt{2gh}.$$

Find the volume:

$$Q=vA=A\sqrt{2gh}.$$

Find the mass:

$$m=Q\rho=\rho A\sqrt{2gh}=1000·3·10^{-4}\sqrt{2·2·9.8}=\\=1.88\text{ kg/s}.$$