A hemispherical bowl is made of 1 cm thick steel. The inside radius of the bowl is 4 cm. The volume of the steel (in cm3) used in making the bowl is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 40π
Inner radius (r₁) = 4 cm
Outer radius (r₂) = 5 cm (since thickness is 1 cm)
Volume of outer hemisphere = (2/3)π(5³) = (250/3)π
Volume of inner hemisphere = (2/3)π(4³) = (128/3)π
Volume of steel = (250/3)π - (128/3)π = (122/3)π = 40π