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Question
A vessel is in the form of a hollow hemisphere mounted by a hollow cylinder. The diameter of the hemisphere is 14 cm and the total height of the vessel is 13 cm. Find the inner surface area of the vessel. [Use `pi = 22/7`]
Solution
It can be observed that radius (r) of the cylindrical part and the hemispherical part is the same (i.e., 7 cm).
Height of hemispherical part = Radius = 7 cm
Height of cylindrical part (h) = 13 − 7 = 6 cm
Inner surface area of the vessel = CSA of cylindrical part + CSA of hemispherical part
= 2πrh + 2πr2
Inner surface are of vessel = `2 xx 22/7 xx 7 xx 6+2 xx 22/7 xx 7 xx 7`
= 44 (6 + 7)
`= 44xx13`
= 572 cm2
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