Question

A well of diameter 2 m is dug 14 m deep. The earth taken out of its is spread evenly all around it to a width of 5 m to from an embankment. Find the height of the embankment.

Answer 1

Let n be the required height of the embankment.

The shape of the embankment will be like the shape of a cylinder of internal radius 1 m and external radius (5 + 1) m = 6 m [figure].

The volume of the embankment will be equal to the volume of the earth dug out from the well.

Now, the volume of the earth = volume of the cylindrical well

Hence, the required height of the embankment = 0.4 m