A small object sits 120 cm from the axis of a disc that turns at a steady 33 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 1.2 m/s². What is the smallest radius rmin for a curve taken at 240 km/h?
In a fairground rotor, riders stand against the wall of a vertical cylinder of radius 3.7 m. When it spins fast enough the floor drops away and friction holds them up. The coefficient of static friction is 0.3. Use g = 9.81 m/s². Find the smallest rotation rate n in revolutions per minute.
In a fairground rotor, riders stand against the wall of a vertical cylinder of radius 1.8 m. When it spins fast enough the floor drops away and friction holds them up. The coefficient of static friction is 0.3. Use g = 9.81 m/s². Find the smallest angular speed ω in rad/s.
A curve of radius 170 m is banked at 18°, and the coefficient of static friction between tyres and road is 0.1. Use g = 9.81 m/s². Find the lowest speed vmin at which a car can take the curve without sliding down the bank.
A 5 kg cart is released from rest at a height of 30.8 m on a frictionless track and runs through a vertical loop of radius 7 m. Use g = 9.81 m/s². Find the normal force Nbottom of the track on the cart at the bottom of the loop.
Answer key
- 1. ac = 14.33 m/s²
- 2. rmin = 3704 m
- 3. n = 28.39 rpm
- 4. ω = 4.262 rad/s
- 5. vmin = 19.06 m/s
- 6. Nbottom = 480.7 N
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