Question

find the sodium of a sphere who's surface area is 154cm2​

Answer 1

Answer:

Step-by-step explanation:

Let 'r' be the radius of sphere

Surface area of sphere = 4πr2  

⇒ 154 = 4πr2   ⇒  154 = 4 x 22/7 x r2

⇒ r2  = 154 x 7/4 x 22 = 49/4

⇒ r = 7/2 cm   = 3.5 cm

Volume of the sphere=  3 /4 πr³

=  3 /4 ×   22 /7 ×(3.5)³  

=   179.67cm³

Answer 2

Appropriate Question :

›»› Find the radius of a sphere whose surface area is 154 cm².

Answer :

›»› The radius of a sphere is 3.5 cm.

Step-by-step explanation :

Given :

• Surface area of sphere = 154 cm².

To Find :

• Radius of a sphere = ?

Formula required :

To find the radius of a sphere we use the formula of surface area a sphere.

Formula of surface area of sphere to calculate the radius of a sphere is given by,

→ Surface area of sphere = 4πr².

Here,

• The value of π is 22/7.
• r is the Radius of sphere.

Units,

• The unit of surface area is cm².
• The unit of radius is cm.

Solution :

As we are given with the surface area of sphere and we need to find the surface area of sphere then we know the required formula, that is,

→ Surface area of sphere = 4πr².

By using the formula of surface area of sphere to calculate the radius of a sphere and substituting the given values in the formula, we get :

→ 154 = 4 × 22/7 × r²

→ 154 = 88/7 × r²

→ 154 × 7 = 88 × r²

→ 1078 = 88 × r²

→ 1078 = 88r²

→ 88r² = 1078

→ r² = 1078/88

→ r² = 49/4

→ r = √(49/4)

→ r = 7/2

→ r = 3.5.

Hence, the radius of a sphere is 3.5 cm.