Question

In a village a well with 10 m inside diameter , is dug 14 m deep .Earth taken out is spread all around to a width of 5m to form an embankment . Find the height of embankment.

Answer 1

radius of well = 5 m

depth = 14 m

volume of earth taken out = πr² h = π×(5)²×14= 1100 m³

now, it is spread to form embankment, which is in the form of hollow cylinder,

inner radius, r= 5 m

outer radius = 5 +5 = 10 m

height= h

then, 1100 = π×h(10²- 5²)

⇒h = 350/75 = 14/3 = 4.67 m