Question

A well of diameter 3m ,dug 14m deep. The earth taken out of it has been spread evenly all around it in the shape of a circular ring of width 4m to form an embankment. Find the height of the embankment.

Answer 1

Solution:-

Height of the well = 14 m
Diameter of the well = 3 m
So, Radius of the well = 3/2 m
Volume of the earth taken out of the well = πr²h
= 22/7*(3/2)²*14
= 99 cu m
Outer radius of the embankment = R = (3/2 + 4)m = 11/2 m
Area of embankment = outer area - inner area
⇒ = πR² - πr²
= 22/7*[(11/2)² - (3/2)²]
= 22/7*[(121/4) - (9/4)]
= 22/7 × 112/4
= 88 m²
Height of the embankment = Volume/Area
= 99/88
Height of the embankment = 1.125 m
Answer.