A small object sits 5 cm from the axis of a disc that turns at a steady 200 revolutions per minute. Find its centripetal acceleration ac.
Circular motion worksheet with answers
For passenger comfort the centripetal acceleration on a railway curve must not exceed 0.5 m/s². What is the smallest radius rmin for a curve taken at 120 km/h?
A road engineer wants cars to take a curve of radius 230 m at 40 km/h without relying on friction. Use g = 9.81 m/s². Find the banking angle θ.
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 40° with the vertical (a conical pendulum). Use g = 9.81 m/s². Find the time T for one revolution.
A 0.2 kg ball on a string 1.3 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 curve of radius 50 m is banked at 8°, 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.
Answer key
- 1. ac = 21.93 m/s²
- 2. rmin = 2222 m
- 3. θ = 3.132 °
- 4. T = 1.469 s
- 5. T = 4.424 N
- 6. vmax = 12.07 m/s
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