Question

A particle moving in a uniform circle makes 30 revolutions per minute. If the radius of the circle is 20 cm the speed of the particle is:

• A. 0.63 m/s
• B. 6.3 m/s
• C. 6.3 mm/s
• D. 0.63 cm/s

Answer 1

The correct option is A 0.63 m/s

The angular velocity of the particle is $30\times 2\pi /60=\pi$ radians/sec
The speed of the particle is $v=R\omega =0.2\times \pi =0.2\pi =0.63$ m/s