Mathematics 9709 · AS & A Level · Differentiation

Differentiation — practice question

A spherical balloon's volume is rising at a steady rate of $50\text{ cm}^3$ per second.

(main)[4]

Find how fast the radius is increasing when the radius is $10\text{ cm}$. $[\text{Volume of a sphere} = \frac{4}{3}\pi r^3.]$

Worked solution & mark scheme

This 4-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Applies $\frac{dv}{dr} = 4\pi r^2$” …