From a tap of inner radius $0.75\ cm$, water flows at the rate of $7\ m$ per second. Find the volume in litres of water delivered by the pipe in one hour.

 Given:

From a tap of inner radius $0.75\ cm$, water flows at the rate of $7\ m$ per second. 

To do:

We have to find the volume in litres of water delivered by the pipe in one hour.

Solution:

Inner radius of the tap $= 0.75\ cm$

Speed of the flow of water $= 7\ m/s$

Time $= 1$ hour

Therefore,

Length of flow of water $(h) = 7 \times 60 \times 60\ m$

$= 25200\ m$

Volume of water delivered by the pipe in one hour $= \pi r^2h$

$=\frac{22}{7} \times \frac{0.75}{100} \times \frac{0.75}{100} \times 25200$

$=\frac{22}{7} \times \frac{3}{400} \times \frac{3}{400} \times 25200$

$=\frac{44550}{10000}$

$=4.455 \mathrm{~m}^{3}$

$=4.455 \times 1000\ l$

$=4455$ litres