Question

A farmer runs a pipe of internal diameter $20cm$ from the canal into a cylindrical tank in his field which is $10m$ in diameter and $2m$ deep. If water flows through the pipe at the rate of $3km/h$, in how much time will the tank be filled?

Answer 1

Volume of pipe $=$ Volume of tank

$\Rightarrow \pi r^{2}h=\pi R^{2}H\Rightarrow {\left(\frac{10}{100}\right)}^2\times h={\left(5\right)}^2\times 2$

$\Rightarrow \frac{h}{100}=50\Rightarrow h=5000m=5km$

speed of water $=$ 3km/hr

Time taken to fill tank $=\frac{5}{3}hr=\frac{5}{3}\times 60min=100min$