Question

How many cubic metres of earth must be dug-out to sink a well 21 m deep and 6 m diameter?

Answer 1

The volume of the earth that must be dug out is similar to the volume of the cylinder which is equal to πr²h.
Height of the well =21 m
Diameter of the well= 6 m
∴ Volume of the earth that must be dug out = (π (3²) (21)) m³= 594 m³