Question

a well with 10meter inside diameter is that 14meter deep. earth taken out of it is spread all around it to width of 5meter to form an embankment. find the height of the 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