What is Collision?
A '''collision''' occurs when two objects come in contact with each other. All collisions have the same [[momentum]] before and after a collision. of collisions include car crashes, bouncing a ball, and playing pool. Collisions are made from two smaller sections called elastic and inelastic collisions. == Elastic Collisions == [[File:To pot the red.jpg|thumb|right|Elastic collisions]] In the case of playing pool or bouncing a ball, an elastic collision occurs. An elastic collision generally occurs when an elastic or hard object experiences a collision that bounces off another elastic or hard object, where the [[kinetic energy]] and momentum are the same before and after the collision. In an experiment, a small amount of energy will still be lost because of the [[friction]] between the surface and the objects. == Inelastic Collisions == In the case of a car crash, an inelastic collision occurs. An inelastic collision generally occurs when a soft object experiences a collision that does not result in a bounce. Kinetic energy is lost during this type of collision because the energy is transformed into other forces. The momentum is the same before and after the collision. == Two Dimensional Collisions == In the case of a two dimensional collision, the rules in elastic and inelastic collision are still the same, but [[vector]]s are used to find the momentum before or after a collision. == Sources == Duncan, Tom. ''Advanced Physics for Hong Kong: Volume 1 Mechanics & Electricity''. John Murray Ltd, 1995. Wai, Loo Kwok. ''Longman A-Level Course in Physics: Volume 1''. Pearson Education South Asia Pte Ltd, 2003. [[Category:Mechanics]]