Question

A well 14 m inside diameter is dug 15 deep . Earth taken out is spread all around to a width of 7 m to form an embankment. Find the height of the embankment .​

Answer 1

Answer:

the height of the embankment =5m

Explanation:

volume of earth taken out = πr^2d

=22/7x(7)^2x15

=2310 m^3

volume of embankment = base area x height

= (π(r+7)^2-πr^2)height

r=7 m

both volumes will be equal

2310 = (22/7x14^2 - 22/7x7^2)xheight

2310 =462xheight

height = 5m

Answer 2

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⇛Volume of the earth dug out

= π r^2 h

⇛22 / 7 ×( 14 / 2 ) ^ 2 × 15 m ^ 3 = 2310 m ^ 3 .

⇛Area of the embankment ( Shaded portion) = π ( R^2 - r ^ 2 )

⇛22 / 7 [ ( 14 )^ 2 - ( 7 ) ^ 2 ] = 22 / 7 ( 196- 49) = 462 m ^ 2

⇛Height of the embankment = Volume of the earth dug out / Area of the embankment = 2310 / 462 = 5 m.

⇛Hence,

Height of the embankment

= 5 m.

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