Question

If radii of two spheres are in ratio 5:1 find the ratio of surface area

Answer 1

Step-by-step explanation:

Ratio of radius of the sphere is 2:3

so r1/r2=2/3

¤ ratio is surface areas =4π(r1)^2/4π(r2)^2

=r1^2/r2^2/

=(r1/r2)^2

so from first r1/r2=2/3

=(2/3)^2

=2^2/3^2

=4/9

hence answer is 4/9

¤ ratio of volume of spheres

= [(4πr^3)/3]/(4πr^3)/3

after cutting =r1^3/r2^3

r1/r2=2/3

so r1^3/r2^3=(2/3)^3

=8/27

Answer 2

the answer is 25/1

Step-by-step explanation:

let radius be r1 and r2

r1/r2= 5/1

r1=5r2 .....(1)

surface area of sphere = 4πr^2

ratio of surface area =4π(r1)^2/4π(r2)^2

=(5r)^2 /(r)^2 ( from (1))

=25/1