Satellite orbiting Earth
Circular Motion - OCR A-Level Physics
- Satellite orbiting EarthCircular motion example: gravitational attraction provides the centripetal force.: gravitational attraction provides centripetal forceThe resultant force directed towards the centre of a circular path that causes an object to move in a circle. It is not a separate force but the net force providing circular motion..
- Car on flat roadCircular motion example: friction between tyres and road provides the centripetal force.: static friction between tyres and road provides centripetal forceThe resultant force directed towards the centre of a circular path that causes an object to move in a circle. It is not a separate force but the net force providing circular motion..
- Electron orbiting a nucleusCircular motion example: the electrostatic (Coulomb) force provides the centripetal force.: electrostatic (CoulombThe SI unit of chargeA property of matter that causes it to experience a force in an electromagnetic field. Measured in coulombs (C).. One coulomb is the chargeA property of matter that causes it to experience a force in an electromagnetic field. Measured in coulombs (C). transferred by a current of 1 A in 1 second.) force provides centripetal forceThe resultant force directed towards the centre of a circular path that causes an object to move in a circle. It is not a separate force but the net force providing circular motion..
- Clothes in a washing machine drumCircular motion example: the drum pushes clothes inwards; when gaps appear, clothes move tangentially.: normal contact force from the drum wall provides centripetal force. Water escapes through holes when contact force is insufficient.
- Planet orbiting the SunCircular motion example: gravitational attraction provides the centripetal force.: gravitational attraction provides centripetal force.
- Ball on a string (horizontal)Circular motion example: the tension provides the centripetal force.: horizontal component of string tension provides centripetal force.
Examiner Tips and Tricks
- A common exam question gives a scenario and asks you to identify the force providing the centripetal force.
- Always name the specific real force (gravity, friction, tension, normal reaction) - never just say 'centripetal force'.