Question

The area of cross-section of a pipe is 5.4 cm² and water is pumped out of it at the rate of 27 km/hr. Find in litres the volume of water which flows out of the pipe in one minute.

Answer 1

Given:

Area of cross-section = 5.4 cm²

Speed = 27 km/hr

Time = 1 minute

Step-wise calculation:

1. Convert speed to cm/s:

27 km/hr

= `27 × (5/18) m//s` 

= 7.5 m/s

= 7.5 × 100 cm/s

= 750 cm/s

2. Volume flow per second

= Area × Speed

= 5.4 cm² × 750 cm/s

= 4050 cm³/s

3. Volume in one minute

= 4050 cm³/s × 60 s

= 243000 cm³

4. Convert to litres (1 litre = 1000 cm³):

243000 cm³

= 243 litres

Volume of water flowing out in one minute = 243 litres.