For passenger comfort the centripetal acceleration on a railway curve must not exceed 0.8 m/s². What is the smallest radius rmin for a curve taken at 240 km/h?
Circular motion worksheet with answers
A small object sits 45 cm from the axis of a disc that turns at a steady 30 revolutions per minute. Find the speed v of the object.
A curve of radius 390 m is banked at 18°. At what speed v can a car take it with no friction needed at all? Use g = 9.81 m/s².
A car takes a flat curve of radius 80 m. The coefficient of static friction between tyres and road is 0.4. Use g = 9.81 m/s². Find the highest speed vmax at which the car can take the curve without skidding.
A ball on a string 0.5 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 curve of radius 170 m is banked at 20°, and the coefficient of static friction between tyres and road is 0.2. Use g = 9.81 m/s². Find the highest speed vmax at which a car can take the curve without sliding up and out.
Answer key
- 1. rmin = 5556 m
- 2. v = 1.414 m/s
- 3. v = 35.26 m/s
- 4. vmax = 17.72 m/s
- 5. vmin = 2.215 m/s
- 6. vmax = 31.85 m/s
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