A well of diameter 3 m is dug 14 m deep. The earth taken out

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

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he shape of well will be cylindrical.
Depth (h1) of well = 14m
Radius (r1) of circular end of well =
image
Width of embankment = 4m
From the figure embankment will be in a cylindrical shape having outer radius (r2) as
image
and inner radius (r1) as
image .
Let height of embankment be h2.
Volume of soil dug from well = volume of earth used to form embankment
image
So, height of embankment will be 1.125 m.