Question

7. Find the volume of a sphere whose surface area is 154 cm
$20x \\ \\ \\ 30 -$
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Answer 1

Given :-

• Surface area of sphere = 154 cm

To find :-

• Volume of sphere

Solution :-

As we know that

★ Surface area of sphere = 4πr²

→ 154 = 4πr²

→ 154 = 4 × 22/7 × r²

→ 154 = 88/7 × r²

→ r² = 154 × 7/88

→ r² = 12.25

→ r = √12.25 = 3.5cm

Now, volume of sphere

→ 4/3 πr³

→ 4/3 × 22/7 × 3.5 × 3.5 × 3.5

→ 4/3 × 22 × 0.5 × 3.5 × 3.5

→ 539/3

→ 179.6cm³

Hence,

• Volume of sphere is 179.6cm³

Answer 2

Answer:-

The volume of a sphere is 179.66 (approx)

Step-by-step explanation:-

We know that,

$\sf{Surface \: area= 4 \: \pi \: {r}^{2}}$

Therefore,

First let's find the radius, Let's take π = 22/7

➝ 154 = 4πr²

➝ 154 = 4 × 22/7 × r²

➝ 154 = 88/7 × r²

➝ r² = 154 × 7/88

➝ r² = 77 × 7/44

➝ r² = 12.25

Now, radius = √12.25 = 3.5

Therefore, r = 3.5cm

Now, let's find the volume of the sphere,

We know that,

Volume of sphere = 4/3 πr²

➝ 4/3 × 22/7 × (3.5)²

➝ 539/3

➝ 179.66≈