Question

A thin horizontal circular disc is rotating about a vertical axis passing through its center. An insect is at rest at a point near the rim of the disc. The insect now moves along a diameter of the disc of reach its other end. During the journey of the insect, the angular speed of the disc:

• A. remains unchanged
• B. continuously decreases
• C. continuously increases
• D. first increases and then decreases

Answer 1

The correct option is D first increases and then decreases

Angular momentum $L=I\omega$
$L=m{r}^2\times \omega$
Since $r$ first decrease then increases.
So due to conservation of angular momentum $L$ first increases then decreases.