Question

a well of inner diameter 14 cm is dug to depth of 12 m earth taken out of it has been evenly spread all around it to a width of 7 cm to from an embankment.find the height of the embankment so formed?

Answer 1

Diameter of well = 14 m

∴ Radius (r) of well = 

Depth of well = 12 m

∴ Volume of earth removed to dug a well  



Width of the earth spread to form an embankment = 7 m

∴ Outer radius of the well (R) = 7 m + 7 m = 14 m

Volume of the earth used to form embankment 



Now, volume of earth used to form embankment = Volume of earth removed to form well

462 h = 1848



⇒ h = 4

∴ Height of the embankment = 4 m