If the surface area of a sphere is 2826 cm2 then find its volume. (π

1.	If the surface area of a sphere is 2826 cm2 then find its volume. (π = 3.14)
Answer» Given: Surface area of sphere = 2826 sq.cm. To find: Volume of sphere i. Surface area of sphere = 4πr² ∴ 2826 = 4 x 3.14 x r² 2826 = 282600 = 900 ∴ r²= 2826/4 x 3.14 = 282600/4 x 314 = 900/4 ∴ r² = 225 ∴ r = √225 … [Taking square root on both sides] = 15 cm ii. Volume of sphere = (4/3) πr³ = (4/3) x 3.14 x 15³ = (4/3) x 3.14 x 15 x 15 x 15 = 4 x 3.14 x 5 x 15 x 15 = 14130 cubic cm. ∴ The volume of the sphere is 14130 cubic cm.

If the surface area of a sphere is 2826 cm2 then find its volume. (π = 3.14)

Answer»

Given: Surface area of sphere = 2826 sq.cm.

To find: Volume of sphere

i. Surface area of sphere = 4πr²

∴ 2826 = 4 x 3.14 x r²

2826 = 282600 = 900

∴ r²= 2826/4 x 3.14 = 282600/4 x 314 = 900/4

∴ r² = 225

∴ r = √225 … [Taking square root on both sides]

= 15 cm

ii. Volume of sphere = (4/3) πr³

= (4/3) x 3.14 x 15³

= (4/3) x 3.14 x 15 x 15 x 15

= 4 x 3.14 x 5 x 15 x 15

= 14130 cubic cm.

∴ The volume of the sphere is 14130 cubic cm.