For passenger comfort the centripetal acceleration on a railway curve must not exceed 1.2 m/s². What is the smallest radius rmin for a curve taken at 250 km/h?
Circular motion worksheet with answers
A 1700 kg car drives around a flat curve of radius 120 m at a constant 17 m/s. Find the inward (centripetal) force Fc needed.
A small ball on a string of length 0.7 m moves in a horizontal circle so that the string makes a constant angle of 15° with the vertical (a conical pendulum). Use g = 9.81 m/s². Find the time T for one revolution.
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 curve of radius 50 m is banked at 18°, and the coefficient of static friction between tyres and road is 0.15. Use g = 9.81 m/s². Find the highest speed vmax at which a car can take the curve without sliding up and out.
A 1.4 kg ball on a light string 1.2 m long is swung in a vertical circle. At the lowest point its speed is 8 m/s. Ignore air resistance and use g = 9.81 m/s². Find the tension Ttop in the string at the highest point.
Answer key
- 1. rmin = 4019 m
- 2. Fc = 4094 N
- 3. T = 1.65 s
- 4. vmax = 20.78 m/s
- 5. vmax = 15.65 m/s
- 6. Ttop = 5.997 N
Full step-by-step solutions: practise this topic on examproblems.com.