The area of cross section of a pipe is 10 sq. cm and the speed of water flowing throught it is 20 cm/s. How long will it take to fill a tank whose capacity is 240 litres?
20 minutes.
Area of cross section = 10 cm2
speed of water = 20cm/s
Volume of water flowing out in one second = area of cross section x speed of water
= 10 x 20
= 200 cm3 = 0.2 litres \([1 litre ~=~ 1000 ~cm^3]
∴ time taken to fill 1 litre = 5 seconds
∴ time taken to fill 240 litres = 240 x 5 = 1200 seconds or 20 minutes.