If the radius of a balloon is doubled by pumping air into it, find the ratio of the two surface areas. (Should I take the 2nd radius as '2r'???) Share with your friends Share 0 Varun.Rawat answered this Let the original radius, r1 = rNow, original surface area = S1 = 4πr12 = 4πr2Now, new radius, r2 = 2rNew surface area = S2 = 4πr22 = 4π2r2 =16πr2 Now, S1S2 = 4πr216πr2 = 14 6 View Full Answer Sameer N answered this let the radius of ballon be 1cm after pumping air radius be 2cm required ratio : intial surafec area/surface area after pumping air = 4pier2/ 4pier2 = 12/22 = 1/4 = 1:4 5
