A spherical balloon has a variable radius. The rate at which its volume is increasing with respect to its radius when radius is 5 cm is : |
$100\pi \, cm^2$ $10\pi \, cm^2$ $20\pi \, cm^2$ $\frac{500}{3}\pi \, cm^2$ |
$100\pi \, cm^2$ |
The correct answer is Option (1) → $100\pi \, cm^2$ $v=\frac{4}{3}πR^3$ so $\frac{dv}{dR}=4πR^2$ $\left.\frac{dv}{dR}\right]_{R=5}=100\pi \, cm^2$ |