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Question
When a disc rotates with uniform angular velocity, which of the following is not true?
Options
The sense of rotation remains same.
The orientation of the axis of rotation remains same.
The speed of rotation is non-zero and remains same.
The angular acceleration is non-zero and remains same.
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Solution
The angular acceleration is non-zero and remains same.
Explanation:
The rate of change of angular velocity is defined as angular acceleration. If the particle has angular velocity ω1 at time t1, and angular velocity ω2 at time t2, then angular acceleration α = ω2 – ω1/t2 – t1
When the disc is rotated with constant angular velocity, the angular acceleration of the disc is zero. Because we know that angular acceleration
α = ∆ω/∆t
Here ω is constant, so ∆ω = 0.
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