Question

The radius of a spherical balloon increases from 5cm to 7.5 cm when it is formed into the race find the ratio of their surface area of a value in the two cases ? Please help me out of this question

Answer 1

Let r1 be the radius of smaller balloon = 5 cm

and r2 be the radius of larger balloon = 7.5 cm

Surface area of sphere =

$4\pi \: r^{2}$

therefore, ratio of the surface = surface area of the smaller balloon by surface area of the larger balloon

$r1^{2} by \: r2^{2}$

= 5 × 5 / 75 × 75

= 1 / 225

Thus, the required ratio of the surface areas = 1/225