Question

A well with 10 m inside diameter is dug 14 m deep. Earth taken out of it is spread all around to a width of 5 m to form an embankment. Find the height of embankment.​

Answer 1

Well with 10m diameter is dug 14m deep.

Cylindrical radius=

$\frac{10}{2} = 5m$

Volume= πr²h

$\frac{22}{7} \times 5 \times 5 \times 14$

=1100 cubic metre

Is taken out and spread width of 5m.

R1=5+5= 10m

r= 5m

V=(R²-r²)h

1100=

$\frac{22}{7} ( {10}^{2} - {5}^{2})h$

350=(100−25)h

$h = \frac{350}{75} = \frac{14}{3}$

⇒h=4.66m

Hence, the answer is 4.66m.

Hope it helps.