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Concepts Of Physics MCQ Edition [Volume 1]PhysicsRotational Mechanics

A block is suspended from a string wrapped on a disc of radius 20 cm , which is free to rotate about its fixed horizontal axis. If the angular speed of the disc is 10 rad/s at a particular instant, at what speed is the block descending at that instant?

Options

  1. A2 m/s
  2. B0.5 m/s
  3. C20 m/s
  4. D200 m/s

Correct answer

A. 2 m/s

Step-by-step solution

Given, radius of the disc, R = 20 cm = 0.2 m Angular speed of the disc, = 10 rad/s The speed of the descending block is equal to the tangential speed of the points on the rim of the disc. v = R v = 0.2 10 = 2 m/s

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