Question

In the middle of a rectangular field measuring 30 m × 20 m, a well of 7 m diameter and 10 m depth is dug. The earth so removed is evenly spread over the remaining part of the field. Find the height through which the level of the field is raised.

Answer 1

Radius of dug  `= 7/2 m`

Depth of dug = 10 m

The volume of dug

`= pi(7/2)^2 xx 10`

`= 22/7 xx 49/4 xx 10`

The volume of dug = 385 m³

Let the height through which the level of the field is raised will be x.

But, volume of dug = volume of earth spread over field.

`385 = 30 xx 20 xx x `

    `x = (385) / (30 xx 20)`

    `x = 68.6cm`