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 120 km/h?
Circular motion worksheet with answers
A 1800 kg car drives around a flat curve of radius 100 m at a constant 10 m/s. Find the inward (centripetal) force Fc needed.
A car takes a flat curve of radius 45 m. The coefficient of static friction between tyres and road is 0.8. Use g = 9.81 m/s². Find the highest speed vmax at which the car can take the curve without skidding.
A car takes a flat curve of radius 45 m. The coefficient of static friction between tyres and road is 0.5. Use g = 9.81 m/s². Find the highest speed vmax at which the car can take the curve without skidding.
A curve of radius 280 m is banked at 30°, and the coefficient of static friction between tyres and road is 0.4. Use g = 9.81 m/s². Find the lowest speed vmin at which a car can take the curve without sliding down the bank.
A 1.3 kg ball on a string 1.2 m long is swung in a vertical circle. At the lowest point it moves at 8 m/s. Use g = 9.81 m/s². Find the tension T in the string at the lowest point.
Answer key
- 1. rmin = 1389 m
- 2. Fc = 1800 N
- 3. vmax = 18.79 m/s
- 4. vmax = 14.86 m/s
- 5. vmin = 19.89 m/s
- 6. T = 82.09 N
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