For passenger comfort the centripetal acceleration on a railway curve must not exceed 1.5 m/s². What is the smallest radius rmin for a curve taken at 300 km/h?
Circular motion worksheet with answers
A 1200 kg car drives around a flat curve of radius 70 m at a constant 26 m/s. Find its centripetal acceleration ac.
A road engineer wants cars to take a curve of radius 390 m at 90 km/h without relying on friction. Use g = 9.81 m/s². Find the banking angle θ.
A car takes a flat curve of radius 35 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 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?
A 2 kg cart is released from rest at a height of 21 m on a frictionless track and runs through a vertical loop of radius 6 m. Use g = 9.81 m/s². Find the normal force Ntop of the track on the cart at the top of the loop.
Answer key
- 1. rmin = 4630 m
- 2. ac = 9.657 m/s²
- 3. θ = 9.278 °
- 4. vmax = 15.5 m/s
- 5. vmin = 2.971 m/s
- 6. Ntop = 39.24 N
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