Question

A hemispherical hollow bowl has material of volume cubic `(436π)/3` cubic cm. Its external diameter is 14 cm. Find its thickness

Answer 1

External radius of a hemisphere (R) = 7 cm

Volume of a hemi-spherical bowl = `(436pi)/3` cm³

`2/3 pi("R"^3 - "r"^3) = (436pi)/3`

`2/3 pi(7^3 - "r"^3) = (436pi)/3`

`2/3 (343 - "r"^3) = 436/3`

343 − r³ = `436/3 xx 3/2`

343 − r³ = 218

343 − 218 = r³

125 = r³

⇒ 5³ = r³

r = 5

Internal radius = 5 cm

Thickness of the hemisphere

= (7 – 5) cm

= 2 cm