Question

a well of diameter 3 cm is dug 21m deep. The earth taken out of it has been spread evenly all around it to a width of 4 m to form an embankment Find the height of the embankment

Answer 1

The shape of well will be cyindrical,Depth(h1) of well=21mRadius (r1) of the circular end of well=42=2mWidth of embankment=3mfrom figure, it can be observed that our embankment will be in cylindrical shape having outer radius(r2) as=3+2=5mLet the height of embankment be h2.Volume of soil dug from well=volume of earth used to form embankmentπr12h1=π(r22−r12)×h2π(2)221=π(52−22)×h24×21=21×h2h2=4m
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