# Physics lab colliding two cars into each other

#### cindy!

hello,

The other day in class i completed a lab colliding two cars into each other 3 times. The first time velcro was attached to the cars so they stuck together after the collision, the second time a spring was attached to one of the cars and the third time it was just the plain bumpers.

I undertstand that the spring bumper is an elastic collision because energy is conserved. And that the velcro is a completely inelastic collision because the kinetic energy is shared and the objects stick together after the collisions. And finally, that the hard bumper is an inelastic collision because kinetic energy is not conserved.

Well, my question is does anyone know what these graphs would look like? We found the graphs while the lab was done but i do not have the program on my home computer. I already tried google but i cannot seem to find them. Im just looking for the basic graph outline..

Thanks for any help.

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#### robphy

Homework Helper
Gold Member
You can start with the equations for a collision [in one dimension] and work out the final velocities in terms of the initial velocities. Those equations will provide you with the plots you seek.

#### KingNothing

Graphs of what? Graphs can often compare two, three, or even more different values or measurements.

#### robphy

Homework Helper
Gold Member
They are probably graphs of the position-vs-time or velocity-vs-time of one or both of the carts, as recorded by a "Sonic Ranger".

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