Further Mechanics

• Angular Displacement

  In circular motion, the angle turned through. Measured in radians or degrees.
• Angular Velocity

  The angular displacement per unit time, measured in radians or degrees per second. It is different from angular speed as it is defined in either a clockwise or anticlockwise direction.
• Centripetal Acceleration

  As a body follows an orbit its direction constantly changes, this produces a constantly changing velocity and the centripetal acceleration is needed to cause this change in velocity.
• Centripetal Force

  A force felt towards the centre of an object's orbit due to the centripetal acceleration.
• Conservation of Momentum

  In a closed system with no external forces the momentum of the system before an event is equal to the momentum of the system after the event.
• Elastic Collision

  When the kinetic energy of a system before an event is equal to the kinetic energy of the system after the event. Impulse: The change of momentum of an object when a force acts on it. Equal to the area underneath a force-time graph.
• Inelastic Collision

  When the kinetic energy of a system before an event is not equal to the kinetic energy of the system after the event. The kinetic energy has been transferred to other forms.