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Centripetal forces review

Review the key concepts, equations, and skills for centripetal forces, including that centripetal force is the net force in the radial direction.

Key terms

Term (symbol)Meaning
Centripetal force (F, start subscript, c, end subscript)Net force acting in the direction towards the center of a circular path, causing centripetal acceleration. Direction is perpendicular to the object’s linear velocity. Also sometimes called radial force.


EquationSymbol breakdownMeaning in words
\Sigma, F, start subscript, R, end subscript, equals, m, a, start subscript, c, end subscripta, start subscript, c, end subscript is centripetal acceleration, m is mass, and \Sigma, F, start subscript, R, end subscript is net force in radial direction (or centripetal force)Net radial force is directly proportional to the product of the object's mass and centripetal acceleration.

Common mistakes and misconceptions

  • Centripetal force is not a type of force. Centripetal force is a net force is the sum of the force vectors pointing in the radial direction. It could be the component of a force, the sum of multiple forces, or the difference of two radial vectors.
  • People mistakenly think objects moving in a circular path are acted upon by an outwards pointing force. When you turn in a circle, it may feel like something is pulling you outwards from the turn, but that’s your inertia trying to resist a change in motion.

Learn more

For deeper explanations of centripetal force, see our video introducing centripetal force using flaming test balls.
To check your understanding and work toward mastering these concepts, check out the exercise on centripetal forces.

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