Question

Marcus is building a model of Earth using a sphere with a surface area of 400 TT

SA
square inches. Use the formular = where r is the radius of the sphere and SA
is the surface area, to find the radius of the sphere Marcus is using for his model.
41

Answer 1

r = 6.69 inches

Explanation:

We have,

Marcus is building a model of Earth using a sphere with a surface area of
`400\pi\ \text{inch}^2`.

It is required to find the radius of the sphere Marcus is using for his model.

The surface area of a circular shaped object is given by :

`A=(4)/(3)\pi r^3`

r is radius

`r=((3A)/(4\pi))^(1/3)\\\\r=((3* 400\pi)/(4\pi))^(1/3)\\\\r=6.69\ \text{inch}`

So, the radius of the sphere is 6.69 inches.