Question

A sphere has a volume of 850 m^3 find its surface area

Answer 1

SA ≈ 434.5 cm²

Explanation:

The volume (V) of a sphere is calculated as

V =
`(4)/(3)`πr³ ( r is the radius )

The surface area (SA) is calculated as

SA = 4πr²

To find r use the volume formula

`(4)/(3)`πr³ = 850 ( multiply both sides by
`(3)/(4)` to clear the fraction )

πr³ = 637.5 ( divide both sides by π )

r³ =
`(637.5)/(\pi )` ( take the cube root of both sides )

r =
`\sqrt[3]{(637.5)/(\pi ) }` ≈ 5.88 cm ( to 2 dec. places )

Then

SA = 4π × 5.88² ≈ 434.5 cm² ( to 1 dec. place )