Question

find the volume of a sphere whose surface area is 249cm²​

Answer 1

Answer:

Volume of sphere = 4/3πr²

surface area of sphere 4πr²

249cm²=4πr²

62.25×3.14 = r²

195.465=r²

13.9808798006=r

Answer 2

$Volume \: of \: Sphere \\ = \: \frac{4}{3} \: \pi \: {r}^{3} (1)$

$4 \times \frac{22}{7} \times {r}^{2} = 249$

${r}^{2} = 249 \times \frac{7}{22} \times \frac{1}{4}$

$= \frac{11.31}{2 \times 2}$

$= \sqrt{ \frac{11.31}{4} }$

$= \frac{3.36}{2} \: \: \: \: \: \: (2)$

$Substituting \: Equation \: 2 \: in \: 1$

$v - \frac{4}{3} \times \frac{22}{7} \times ( \frac{3.36}{4} ) ^{2}$

$= \frac{4}{3} \times \frac{22}{7} \times \frac{3.36}{2} \times \frac{3.36}{2} \times \frac{3.36}{2}$

$= 2 \times 11 \times 1.68 \times 0.48 \times 1.12$

$= 19.86 \: {cm}^{3}$