A uniform circular disc of radius at rest is free to turn about an axis that is perpendicular to its plane and passes through its centre. It is subjected to a torque that produces a constant angular acceleration of . Its net acceleration in at the end of is approximately:
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Given: Radius of the disc, Initial angular velocity, (since it is at rest) Angular acceleration, Time,
Angular velocity at is given by the first equation of rotational kinematics:
The net linear acceleration of a particle on the rim of the disc is the vector sum of its tangential acceleration () and centripetal acceleration ().
Tangential acceleration:
Centripetal (radial) acceleration:
Since and are perpendicular to each other, the magnitude of the net acceleration is:
Therefore, the net acceleration is approximately .
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