The volume of a hemisphere is 2425 1/2 cm3. Find its C.S.A

1.	The volume of a hemisphere is 2425 1/2 cm3. Find its C.S.A
Answer» As, volume of hemisphere = 2425{tex}\\frac { 1 } { 2 } c m ^ { 3 }{/tex}{tex}\\Rightarrow \\frac { 2 } { 3 } \\pi r ^ { 3 } = 2425 \\frac { 1 } { 2 }{/tex}{tex}\\Rightarrow \\frac { 2 } { 3 } \\times \\frac { 22 } { 7 } r ^ { 3 } = \\frac { 4851 } { 2 }{/tex}{tex}\\Rightarrow r ^ { 3 } = \\frac { 4851 \\times 3 \\times 7 } { 2 \\times 2 \\times 22 }{/tex}{tex}\\Rightarrow r ^ { 3 } = \\frac { 441 \\times 3 \\times 7 } { 2 \\times 2 \\times 2 }{/tex}{tex}\\Rightarrow r ^ { 3 } = \\frac { 21 ^ { 3 } } { 2 ^ { 3 } }{/tex}{tex}\\Rightarrow r = \\frac { 21 } { 2 } c m{/tex}So, the curved surface area of the hemisphere ={tex}2 \\pi r ^ { 2 }{/tex}{tex}= 2 \\times \\frac { 22 } { 7 } \\times \\frac { 21 } { 2 } \\times \\frac { 21 } { 2 } = 693 \\mathrm { cm } ^ { 2 }{/tex}

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