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Question
How many cubic metres of earth must be dug to construct a well 7 m deep and of diameter 2.8 m?
Solution
A well is in the form of cylindrical form.
Earth must be dug to construct a well 7 m deep and diameter 2.8 m is equal to the volume of a cylinder with 7 m height and diameter 2.8 m.
Volume of a cylinder = πr2h
= `22/7 xx 2.8/2 xx 2.8/2 xx 7`
= 11 × 2.8 × 1.4
= 43.12 m3
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