For passenger comfort the centripetal acceleration on a railway curve must not exceed 2 m/s². What is the smallest radius rmin for a curve taken at 250 km/h?
Circular motion worksheet with answers
A small object sits 145 cm from the axis of a disc that turns at a steady 90 revolutions per minute. Find its centripetal acceleration ac.
A small ball on a string of length 0.7 m moves in a horizontal circle so that the string makes a constant angle of 35° with the vertical (a conical pendulum). Use g = 9.81 m/s². Find the speed v of the ball.
A small ball on a string of length 1.3 m moves in a horizontal circle so that the string makes a constant angle of 25° with the vertical (a conical pendulum). Use g = 9.81 m/s². Find the time T for one revolution.
A ball on a string 0.7 m long is swung in a vertical circle. Use g = 9.81 m/s². What is the smallest speed vmin at the top for which the string just stays tight?
A ball on a string 0.9 m long is swung in a vertical circle. Use g = 9.81 m/s². What is the smallest speed vmin at the top for which the string just stays tight?
Answer key
- 1. rmin = 2411 m
- 2. ac = 128.8 m/s²
- 3. v = 1.661 m/s
- 4. T = 2.177 s
- 5. vmin = 2.62 m/s
- 6. vmin = 2.971 m/s
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