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 0.1 kg stone is whirled in a horizontal circle of radius 0.5 m on a smooth, level table, held by a string that breaks at a tension of 120 N. Find the highest speed vmax the stone can have.
A car takes a flat curve of radius 45 m. The coefficient of static friction between tyres and road is 0.6. 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 130 m. The coefficient of static friction between tyres and road is 0.7. Use g = 9.81 m/s². Find the highest speed vmax at which the car can take the curve without skidding.
A 0.3 kg ball on a string 1.4 m long is swung in a vertical circle. At the lowest point it moves at 7.5 m/s. Use g = 9.81 m/s². Find the tension T in the string at the lowest point.
A 0.8 kg ball on a string 0.6 m long is swung in a vertical circle. At the lowest point it moves at 3.5 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. vmax = 24.49 m/s
- 3. vmax = 16.27 m/s
- 4. vmax = 29.88 m/s
- 5. T = 15 N
- 6. T = 24.18 N
Full step-by-step solutions: practise this topic on examproblems.com.