Center of mass:  a particular location where all of the mass of an object seems to be located, or concentrated: an average location for the total mass of a system.

Momentum:  Momemtum may be described as inertia in motion.  It is the product of mass times velocity. P = mv

Impulse: A change in the momentum of an object.  It is the product of force times time. J=Ft The impulse may occur over a long or short time period, and with a large or small force applied to make the change in momentum. 

Conservation of momentum:  Momentum isn’t created or destroyed in a given system.  It may be transferred from one object to another.  Only an outside or external force will change the total momentum.

• When comparing a bouncing collision to a collision where an object is brought to a halt, the bouncing object experiences a much larger impulse.
• A hit and stick collision is when one object impacts another, then they stay as one.
• A hit and rebound collision is when one object hits another and they both remain separate.
• An explosion collision is when an object breaks apart.  It may not necessarily be an explosion.

Elastic collision: An elastic collision is one where:

• Momentum is conserved. 
• The objects colliding aren’t deformed or smashed
• Thus no kinetic energy is lost; kinetic energy is conserved also. 
• Ex: billiard ball collisions

Inelastic collisions: An inelastic collsion is one where:

• Momentum is still conserved, but kinetic energy is lost.
• The lost kinetic energy will be transformed into other types.
• The objects often interlock and stick together, they may also be deformed and mangled.
• Ex: car crash

This tutorial describes the concept of momentum.  This is very similar to inertia in motion.  Once a moving object has momentum, it may be changed and brought to a halt.  This change in momentum is called impulse.  Anytime there is some type of collision or interaction, momentum is transferred.  This tutorial describes three main types of momentum collisions: hit and stick, hit and rebound, and explosion.  In all of these, the conservation of momentum is observed.  Momentum isn’t created or destroyed, its just transferred from one item to the next.

Specific Tutorial Features:

• Problem-solving techniques are used to work out and illustrate the example problems, step by step.
  
• Animated diagrams to accompany example problems, specifically vector diagrams to show conservation of momentum in 2 dimensions.

Series Features:

• Concept map showing inter-connections of new concepts in this tutorial and those previously introduced.
  
• Definition slides introduce terms as they are needed.
  
• Visual representation of concepts
  
• Animated examples—worked out step by step
  
• A concise summary is given at the conclusion of the tutorial.

Center of mass

Momentum

• Definition
  
• Formula

Impulse

• Formula
  
• Examples
  
• Bouncing versus sticking

Conservation of momentum

• Collsions
  
• Inelastic versus elastic collisions
  
• 2 dimensional collisions