Full Speed Ahead!

If and how a car's direction and speed change after a collision depends on the mass and speed before the collision of the cars involved. For example, two bumper cars move towards each other with the same speed, but one has three times the mass of the other one, In the model experiment the blue car would be three times heavier than the green car. What we could observe would be the following: afther the frontal collison the blue (heavy) car would stop moving, the green (light) car would bounce off with twice the speed. This means that the lighter car has kept its kinetic energy for itself while the heavy car passes all of its kinetic energy onto the light car (it stops moving). In addition to energy we also have to take a look at the momentum.
The observed scenario resembles the law of the conservation of energy and momentum during an elastic collision within a system, which isn't influenced by any outer forces. If we apply the laws of energy and momentum, we can really simply calculate the velocities of the involved cars. Energy and momentum of a car after a collision can be calculated easily, as well.
There are many similar situations like the one with the bumper cars - it's always the same for elastic bodies. Now, think for a while. Do any similar situations come to your mind?

Well? Any idea what the connection is between the rubber balls and the bumper cars? Excellent, then you can take one more step ahead!