Q5 of 26 Page 183

The length of radius of spherical gas balloon increases from 7 cm to 21 cm as air is being pumped into it let us find the ratio of surface arcas of the balloon in two cases.

Given:


Initial radius, r1 = 7cm


Final radius, r2 = 21cm


Formula used:


Surface area of sphere = 4×π×r2



So, Ratio of surface area


⇒ Ratio of surface area


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