Momentum and impulse

• Momentum

  
  

  the product of an object's mass and its velocity.
• Linear Momentum

  A vector quantity with the same direction as the velocity of the object.
• Principle of conservation of linear momentum

  The total linear momentum of an isolated system remains constant (is conserved)
• Impulse

  the product of the resultant/net force acting on an object and the time the net force acts on the object.
• Newton's second law of motion in terms of momentum

  The net (or resultant) force acting on an object is equal to the rate of change of momentum of the object in the direction of the net force
• System

  A small part of space that we are considering when investigating and solving a particular problem.
• Isolated System

  A system on which the net external force is zero. An isolated system excludes external forces that originate outside the colliding bodies, e.g. friction. Only internal forces, e.g. contact forces between the colliding objects, are considered.
• Internal Force

  Force that objects exert on each other within a system, e.g. contact forces between colliding cars.
• External Force

  A force from outside a system that acts on the objects within a system, e.g. applied force, frictional force, air resistance, tension in a rope.
• Elastic Collision

  A collision in which the total kinetic energy of the objects in the system during the collision is conserved.
• Inelastic Collision

  A collision in which the total kinetic energy of the objects in the system during the collision is NOT conserved.