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