Question

To the nearest whole number, what is the surface area of a sphere with a volume of 140 cm3?

Answer 1

we know that V= 4/3 pi r^3

So r^3= 140/ ((4/3) pi)= 33.422538

Hence r= 3.221166

SA = 4 pi r^2
= 4 pi 3.221166^2
= 130.39 cm^2
= 130 cm^2

Answer 2

Answer:
`130\ cm^2`

Explanation:

The volume of sphere is given by :-

`V=(4)/(3)\pi r^3`, where r is radius of sphere.

Given : The volume of sphere =
`140\ cm^3`

`\Rightarrow\ 140=(4)/(3) (3.14) r^3\\\\\Rightarrow\ r^3=(140*3)/(4* (3.14))\\\\\Rightarrow\ r^3=33.4394904459\approx33.44`

Taking cube root on both sides , we get

`r=\sqrt[3]{33.44}=3.22171078046\approx3.22\ cm`

The surface area of sphere is given by :-

`S.A=4\pi r^2\\\\\Rightarrow\ S.A.=4(3.14)(3.22)^2\\\\\Rightarrow\ S.A.=130.227104\approx130\ cm^2`