Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Applications of Derivatives

Question:

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 :

Options:

$100\pi \, cm^2$

$10\pi \, cm^2$

$20\pi \, cm^2$

$\frac{500}{3}\pi \, cm^2$

Correct Answer:

$100\pi \, cm^2$

Explanation:

The correct answer is Option (1) → $100\pi \, cm^2$

$v=\frac{4}{3}πR^3$

so $\frac{dv}{dR}=4πR^2$

$\left.\frac{dv}{dR}\right]_{R=5}=100\pi \, cm^2$