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 1600 kg car drives around a flat curve of radius 30 m at a constant 9 m/s. Find its centripetal acceleration ac.
A 1300 kg car drives over the top of a hump in the road at 13 m/s. The top of the hump is a circular arc of radius 35 m. Use g = 9.81 m/s². Find the normal force N of the road on the car at the top.
A car takes a flat curve of radius 110 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 2 kg ball on a string 1.1 m long is swung in a vertical circle. At the lowest point it moves at 4 m/s. Use g = 9.81 m/s². Find the tension T in the string at the lowest point.
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?
Answer key
- 1. rmin = 5556 m
- 2. ac = 2.7 m/s²
- 3. N = 6476 N
- 4. vmax = 20.78 m/s
- 5. T = 48.71 N
- 6. vmin = 2.215 m/s
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