Interactive Physics Exercise on One-Dimensional Collisions

In this exercise you will use Interactive Physics to explore elastic and inelastic collisions in one dimension. Set up a one-dimensional, head-on collision between two masses (balls). It will help to show grid lines on the screen in order to make the collision exactly head-on. Turn off gravity so that the only forces are the impact forces between the masses when they collide. Choose different values for both the masses and the initial velocities of the two balls.

A. In the first case, set the elasticity of each mass to 1 so that the collision is perfectly elastic. For each mass, measure and record the velocity, momentum, and kinetic energy before and after the collision. Also record the masses.

Is momentum conserved during the collision? What about kinetic energy? Are these results what you expect? Explain.

B. Now set the elasticity of each mass to 0.5 and repeat the above. Is kinetic energy lost? If so, where did it go?

C. Finally, set the elasticity of each mass to zero and run the collision again. Explain what happens and discuss the results.