Question

Water is being pumped out through a circular pipe whose diameter is $p$ cm. If the flow of water is $14p$ cm per second, how many litres of water are being pumped out in one hour? (Take $\pi$ = 22 / 7)

• A. $39.6p^{3}litres$
• B. $33.6p^{3}litres$
• C. $36.6p^{3}litres$
• D. $35.6p^{3}litres$

Answer 1

The correct option is A $39.6p^{3}litres$

In one second, if $14pcm$ of water is flown, then in one hour, length or distance covered by the water $=14p\times 60\times 60=50400pcm$

Radius of pipe $=\frac{p}{2}cm$
Since the pipe is cylindrical in shape, Volume $=\pi {Radius}^2\times height$
Here, height is considered as the distance travelled.
Hence, Volume of water which flows in one hour $=\frac{22}{7}\times {\left(\frac{p}{2}\right)}^2\times 50400p{cm}^3$

$=39600p^3{cm}^3=39600p^3\times 0.001litres$

$=39.6p^{3}litres$