A well with 14m diameter is dug 8m deep. The earth taken out of it has been evenly spread all around it to a width of 21m to form as embankment. Find the height of the embankment.

Explanation

Volume of earth taken out`=pir^2h`

`=392pi`

`r_(outer)`=21+7=28m

`r_(i n n e r)`=7cm

Volume of embankment=Volume of earth taken out

`h(pi(28^2-7^2))=392pi`

`h=0.533m`.