Question

Water flows through a horizontal pipe of varying area of cross section at the rate $15$ cubic metre per minute. Find the radius of pipe where water velocity is $3m{s}^{-1}$

Answer 1

Volume of water flowing per second$=R$

$=\frac{15}{60}$

$=0.25m^3/s$

$R=Av$

$A=R/v$

$A=0.25/3$

$A=\frac{1}{12}{m}^2$

Area of the cross section is $\frac{1}{12}{m}^2$

Radius of pipe $=\frac{\sqrt{1}}{(12\times \pi )}\dots \dots [\because A=\pi r^2]$

$=0.162m$

$=16.2cm$