Water is being pumped out through a circular pipe whose external diameters is 7 cm. If the flow of water is 72 cm per second how many litres of water are being pump out in one hour.
Volume of water that will be pumped out in 1 seconds
= π(7/2)^{2} (72) cu cm.
Volume of water that will be pumped out in one hour
= π(7/2)^{2} (72)(3600) cu cm
= 99,79,200 cu cm
= 9979.2 litres.