Question

The radius of a spherical balloon increases from 9cm to 21cm as air is being pumped into it. Find the ratio of (i) surface areas of the balloon in the two cases (ii) (i) Volumes of the balloon in the two cases.​

Answer 1

Answer:

Answer

Given radius r

1

=7 cm

r

2

=14 cm

Initial surface area (r

1

=7)=4πr

2

=4×

7

22

×7×7

=616 cm

2

Surface area (r

2

=14)=4πr

2

=4×

7

22

×14×14

=2464 cm

2

Ratio of surface area =

2464

616

=

4

1