Mechanical Properties of Fluids PYQs

The cylindrical tube of a spray pump has radius $R$, one end of which has fine holes, each of radius $r$. If the speed of the liquid in the tube is $V$, the speed of ejection of the liquid through the holes is:

The heart of a man pumps $5$ litres of blood through the arteries per minute at a pressure of $150\,\text{mm}$ of mercury. If the density of mercury is $13.6\times10^3\,\text{kg/m}^{3}$ and $g=10\,\text{m/s}^{2}$, then the power of heart in watt is:

Water rises to height $h$ in a capillary tube. If the length of capillary tube above the surface of water is made less than $h$, then: