Question

In a competition, a brave child tries to inflate a huge spherical balloon bearing slogans against child labour at the rate of 900 cubic centimeter of gas per second. Find the rate at which the radius of the balloon is increasing when its radius is 15 cm.

Answer 1

\(\frac{dr}{dt}=\,?,\)

When r = 15 cm

V  = \(\frac{4}{3}\pi r^3 \) 

Differentiating both sides with respect to 't', we get