If the radius of a sphere is mentioned as \(7 \mathrm{~m}\) with an error of \(0.02 \mathrm{~m}\), then the…

If the radius of a sphere is mentioned as \(7 \mathrm{~m}\) with an error of \(0.02 \mathrm{~m}\), then the approximate error in calculating its volume is
  1. \(1.83 \pi \mathrm{m}^3\)
  2. \(2.25 \pi \mathrm{m}^3\)
  3. \(4.39 \pi \mathrm{m}^3\)
  4. \(3.92 \pi \mathrm{m}^3\)

Solution

Radius \((r)=7 \mathrm{~m}\) Error in radius \((d r)=0.02 \mathrm{~m}\) Volume of sphere \((v)=\frac{4}{3} \pi r^3\) differentiate w.r. to ' \(r\) ' on both sides, \(\begin{aligned} & \frac{d v}{d r}=\frac{4 \pi}{3}\left(3 r^2\right) \\ & d v=4 \pi\left(r^2\right) \cdot d r=4 \pi(49) \cdot(0.02) \\ & d v=3.92 \pi m^3 \end{aligned}\) Hence, option (d) is correct.

Asked in: AP EAMCET 2020 (18 Sep Shift 2)

Practice more Applications of Derivatives questions on Aicharya