Question

the water flows straight downward out at the end of circular pipe of radius r=2 mm and velocity =1m/s. It flows in a continuous column, without breaking into drops. What is the flow rate in this column?

Answer 1

Given:

$r=2\:\rm mm=2*10^{-3}\: m$

$v=1\:\rm m/s$

The area of a pipe

$$A=\pi r^2=3.14*(2*10^{-3}\:\rm m)=1.26*10^{-5}\:\rm m^2$$

The flow rate

$$Q=\frac{dV}{dt}=Av\\ =1.26*10^{-5}\:\rm m^2*1\: m/s=1.26*10^{-5}\:\rm m^3/s$$