Application of Derivatives Question - CBSE

Question

Radius of a variable sphere is increasing at $3 ext{ cm/s}$. Rate of increase of volume when radius is $2 ext{ cm}$ is:
(a) $48\pi ext{ cm}^3/ ext{s}$
(b) $36\pi ext{ cm}^3/ ext{s}$
(c) $24\pi ext{ cm}^3/ ext{s}$
(d) $12\pi ext{ cm}^3/ ext{s}$

Accepted Answer

V = (4/3)\pi r^3 \implies dV/dt = 4\pi r^2 dr/dt = 4\pi (4)(3) = 48\pi. [1.0 Mark]

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🎯 Official CBSE Marking Scheme:
Selecting $48\pi ext{ cm}^3/ ext{s}$: 1.0 Mark

Question:

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