Rotational Kinematics & Dynamics
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 to reach its other end. During the journey of the insect, the angular speed of the disc.
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Answer: (c)
- No external torque about the axis, so = constant.
- As the insect moves from rim towards centre, decreases; from centre to the other rim, increases.
- So first increases and then decreases: answer (c).