Question

The surface area of a sphere is 2464 cm². If its radius be doubled, what will be the surface area of the new sphere?

Answer 1

Let the radii of the given sphere and the new sphere be r and R, respectively. 

We have,

R = 2r and the surface area of the given sphere = 24 cm²

`i.e. 4pir^2 = 2464  cm<sup>2</sup>`

The surface area of the given sphere = 2464 cm²                     

`i.e 4pir^2 = 2426` cm²  

The surface area of the new sphere = 4πR²

`= 4pi (2r)^2` 

`= 4pi (4r)^2` 

`= 4 (4pir^2)`

`= 4xx2464`

`= 9856  cm^2`

So, the surface area of the new sphere is 9856 cm².