Question

Find the volume of a sphere whose surface area is 154 cm 2 .

Answer 1

GIVEN :
Surface area of sphere = 154 cm²
Surface area of sphere = 4πr²
154 = 4 ×(22/7) × r²
154 × 7 = 88r²
r² = (154×7) /88
r² = (7 × 7 )/4
 r² = 49 /4
r = √49/4 = 7/2
r = 7/2 cm
Volume of Sphere = 4/3 πr³
=( 4/3) × (22/7) × (7/2)³
= 4/3 × 22/7 × (7/2) × (7/2) × (7/2)
= (22 × 7 × 7) /(3×2)
=( 22 × 49) / 6= 1078/6 = 179.66 cm³
Volume of Sphere = 179.66 cm³
Hence, the Volume of Sphere is 179.66 cm³.

HOPE THIS WILL HELP YOU...

Answer 2

$\huge{\mathcal{Hi\: there!}}$

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Let $r$ cm be the radius of the sphere.

Now, we know that;

Surface area of sphere = 4 π r²

⇒ 4 × $\frac{22}{7}$ × r² = 154

⇒ r² = $\frac{154 \times 7}{4 \times 22}$

⇒ r² = 12. 25

⇒ r = √12.25

⇒ r = 3.5 cm.

Now,

Volume of sphere = $\frac{4}{3}$ π r³

⇒ $\frac{4}{3} \times \frac{22}{7} \times \frac{35}{10} \times \frac{35}{10}$

⇒ $\frac{539}{3}$

≈ 179 . 67 cm³

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Thanks for the question!

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