A cylindrical tank of diameter 2m is dug and the earth removed from it

1.	A cylindrical tank of diameter 2m is dug and the earth removed from it is spread uniformly all around the tank to form an embankment 2m in width and 1.6m in height. Find the depth of circular tank.
Answer» Ans :- For circular tank external radius R = 3 minternal radius r = 1 m thus volume of embankment V = π× (R^2 - r^2) × h = π× (9-1) × 1.6 = 40.192 m^2 now volume of tank V' = 12 × r^2 ×h = 3.14 × 1 × h since both are equal V = V'thus 3.14 h = 40.192 h = 12.8 m thus height of tank is 12.8 m

A cylindrical tank of diameter 2m is dug and the earth removed from it is spread uniformly all around the tank to form an embankment 2m in width and 1.6m in height. Find the depth of circular tank.

Answer»

Ans :- For circular tank

external radius R = 3 minternal radius r = 1 m

thus volume of embankment

V = π× (R^2 - r^2) × h = π× (9-1) × 1.6 = 40.192 m^2

now volume of tank

V' = 12 × r^2 ×h = 3.14 × 1 × h

since both are equal

V = V'thus 3.14 h = 40.192 h = 12.8 m

thus height of tank is 12.8 m