Circular motion

• Angular speed

  A measure of the speed of an object‘s angular rotation. It is equal to the frequency of rotation multiplied by 2 pi
• Centripetal acceleration

  The acceleration of an object moving in circular motion. any object in circular motion must have an acceleration since the direction of the object, and therefore the velocity of the object, is constantly changing.
• Centripetal force

  The resultant force responsible for an object moving in circular motion. centripetal forces always act towards the centre of the object’s rotation.
• Radian 


  A unit of angle
• Angular displacement (in radians)

  (Arc length)/(radius)
• 360 degrees=2 pi radians
• Angular speed

  (Angular displacement)/(time)
• angular speed = (2 pi)x frequency
• Speed = radius x angular speed
• Acceleration

  Acceleration= speed x angular speed

  acceleration= radius x (angular speed)^2

  acceleration= (speed^2)/(radius)
• Centripetal force

  Force= mass x speed x angular speed

  Force=mass x radius x (angular speed)^2

  Force= mass x ((speed^2)/(radius))