JEE Mains · Physics · STD 11 - 6. system of particles and rotational motion
If the radius of earth is reduced to three-fourth of its present value without change in its mass then value of duration of the day of earth will be _______ hours \(30\) minutes.
- A \(13\)
- B \(15\)
- C \(20\)
- D \(25\)
Answer & Solution
Correct Answer
(A) \(13\)
Step-by-step Solution
Detailed explanation
By conservation of angular momentum \(\mathrm{I}_1 \omega_1=\mathrm{I}_2 \omega_2\) \(\left(\frac{2}{5} \mathrm{MR}^2\right) \frac{2 \pi}{\mathrm{T}_1}=\frac{2}{5} \mathrm{M}\left(\frac{3}{4} \mathrm{R}\right)^2 \frac{2 \pi}{\mathrm{T}_2}\)…
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