A hemispherical bowl is made of iron with a thickness of 0.5 cm. The inner radius is 3 cm. Find the volume of iron used to make the bowl.
Show answer & explanation
Correct answer: C
Explanation
Given:
Inner radius = 3 cm
Thickness = 0.5 cm
By formula:
Volume of hemisphere = (2/3)πr³
Outer radius = 3 + 0.5 = 3.5 = 7/2
Volume of iron = (2/3)π(3.5³ − 3³)
= (2/3)π((7/2)³ − 27)
= (2/3)π(343/8 − 27)
= (2/3)π((343 − 216)/8)
= (2/3)π(127/8)
= (254π)/24
= 127π/12 cm³