ExamBro
ExamBro
MHT CET · Physics · Gravitation

If the density of the earth is doubled keeping radius constant, find the new acceleration due to gravity? \(\left(g=9.8 \mathrm{~m} / \mathrm{s}^{2}\right)\)

  1. A \(9.8 \mathrm{~m} / \mathrm{s}^{2}\)
  2. B \(19.6 \mathrm{~m} / \mathrm{s}^{2}\)
  3. C \(4.9 \mathrm{~m} / \mathrm{s}^{2}\)
  4. D \(39.2 \mathrm{~m} / \mathrm{s}^{2}\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(19.6 \mathrm{~m} / \mathrm{s}^{2}\)

Step-by-step Solution

Detailed explanation

Acceleration due to gravity \(g=\frac{4}{3} \pi \rho G R\)
or \(g \propto d R\)
\(\left[\because \text { density } d=\frac{4}{3} \pi \rho\right]\)
\(
\begin{aligned}
\therefore \quad & \frac{g_{1}}{g_{2}}=\frac{d_{1}}{d_{2}} \\
\frac{g_{1}}{g_{2}} &=\frac{d}{2 d} \quad\left(\because d_{2}=2 d\right) \\
& g_{2}=g_{1} \times 2=9.8 \times 2 \\
& g_{2}=19.6 \mathrm{~m} / \mathrm{s}^{2}
\end{aligned}
\)