Worked example 1 Find the volume of the cylinder. Let π = 3·14
Solution 4 cm 3 cm
Volume of a cylinder = π × radius × radius × height V = πr2
h
This formula appears in the formulae and tables booklet. When doing calculations involving π, use 22
leave answer in terms of π . Otherwise, use the π button on your calculator.
__ 7 or 3 · 14 or
Worked example 2
Holly and Leo set up an infl atable cylindrical pool in their back garden. The diameter of the pool is 3 metres, and it is 0·4 metres high. (i) What is the volume of the pool? (Let π = 22
__ 7 )
(ii) The pool develops a leak and water pours out at rate of 50 litres per hour. How long will it take for all the water in the pool to leak out, given that the pool was completely full at the start? Give your answer in hours and minutes.
Solution (i)
Worked example 3 A cylinder has a radius of 5 cm and a volume of 150 π cm3 Find the height of the cylinder.