Question

a sphere is expanded to a bigger sphere such that its volume increases by a factor of 8 , find the change in its surface area .SPAM WILL BE REPORTED​

Answer 1

Answer:  4 - times

Step-by-step explanation:

Let the radius of sphere initially be r.

Surface area of sphere = 4π r²         ......................(i)

volume of sphere = 4/3 π r³

After the increase in volume by 8,

new volume = 4/3 π R³ = 8 ( 4/3 π r³)

                     => R³ = 8 r³    or R = 2 r

=> New surface area = 4 π ( 2r )² = 4 π ( 4r² )

                                  = 16 π r²         ...........................(ii)

from (i) & (ii) : 4 π r² = 16 π r²

=> 1:4