Search any question & find its solution
Question:
Answered & Verified by Expert
A thin horizontal circular disc is rotating about a vertical axis passing through its centre. An insect is at rest at a point near the rim of the disc. The insect now moves along a diameter of the disc to reach its other end. During the journey of the insect, the angular speed of the disc:
Options:
Solution:
1211 Upvotes
Verified Answer
The correct answer is:
first increases and then decreases
first increases and then decreases
$$
\tau=0
$$
Angular momentum is conserve
$$
\mathrm{I}_1 \omega_1=\mathrm{I}_2 \omega_2 \Rightarrow \omega_2=\frac{\mathrm{I}_1 \omega_1}{\mathrm{I}_2}
$$
$\mathrm{I}_2$ first decreases and then increases
$\therefore \omega$ first increases and then decreases.
\tau=0
$$
Angular momentum is conserve
$$
\mathrm{I}_1 \omega_1=\mathrm{I}_2 \omega_2 \Rightarrow \omega_2=\frac{\mathrm{I}_1 \omega_1}{\mathrm{I}_2}
$$
$\mathrm{I}_2$ first decreases and then increases
$\therefore \omega$ first increases and then decreases.
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.