# The difference between elastic and inelastic collisions? Part 1

What is the difference between Elastic and Inelastic collisions
Joe N
2011
If you want to understand this information better, check the glossary near the end of this wikispace.
Elastic Collisions
If a moving object collides with another moving object or a stationary object, and if after the collision both objects are moving, the kinetic energy of the first object equals the total kinetic energy of the two objects after the collision plus any sound or light formed during the collision. Usually there are calculations in which we think that no kinetic energy is lost. We call such collisions elastic collisions. If the object at the top of its path is still. its speed is equal to zero, so its kinetic energy is zero and it has potential energy. If the bottom of the path is at ground level, the potential energy of the object will be zero and it will have kinetic energy. If the object at the top is moving, it has both kinetic and potential energy.A roller coaster provides a great example illustrating the law of conservation of energy and the use of these rules. When two bodies collide, the momentum they have added together before they collide is the same momentum that they will have after they collide. This is the relation between the kinetic energies before and after impact. When two pool balls collide, it is a perfect example of an elastic collision. Itâ€™s just an elastic collision where the kinetic energy is conserved in one of the pool balls.

Inelastic Collisions
The sudden, forceful collision in direct contact of two objects, such as, for example, a golf club and a ball, a hammer and a nail head, two railroad cars when being coupled together, or a falling object and a floor. Apart from the characteristics of the materials of the two objects, two objects affect the result of impact when the force and the time during which the objects are together.It is a matter of common sense that a hard steel ball dropped on a steel plate will rebound to almost the position from which it was dropped, whereas with a ball of putty or lead there is no rebound. The impact between the steel ball and plate is said to be elastic, and that between the putty or lead balls and plate is inelastic, or plastic; between these extremes there are different degrees of elasticity and the same responses to impact. In a perfectly elastic impact, none of the kinetic energy of the bodies is lost; in a perfect inelastic impact, the loss of kinetic energy is at a maximum.
 Diagram for elastic collisiions

 Diagram for inelastic collision

 Example of Inelastic Collision
 Example of Elastic Collision

Glossary
Kinetic energy- the energy that a moving body or object is producing
Potential energy- the amount of energy that can be produced by a body or object, but is not being produced.
Velocity- the speed of a moving object

Citations

1.collision." Encyclopedia Britannica. Encyclopedia Britannica Online School Edition.
Encyclopedia Britannica, Inc., 2011. Web. 22 Sept. 2011.
<http://school.eb.com/eb/article-9024789>. collision. (2011). In Encyclopedia Britannica. Retrieved from http://school.eb.com/eb/article-9024789 Encyclopedia Britannica Online School Edition, s.v. "collision," accessed September 22, 2011, http://school.eb.com/eb/article-9024789. collision 2011. Encyclopedia Britannica Online School Edition. Retrieved 22 September 2011, from http://school.eb.com/eb/article-9024789 Citations for elastic and inelastic collisions

2.energy, conservation of." Compton's by Britannica. Encyclopedia Britannica Online School Edition.
Encyclopedia Britannica, Inc., 2011. Web. 22 Sept. 2011.
3.1st Author: Knight, Judson
2nd Author: Schlager, Neil
Title: Science of everyday things: volume 2: real-life physics
Publisher Location: Detroit, MI
Publisher: Gale Group