Collision Experiments

The web page has the LabVIEW screens from when I did the experiment. You will obtain your own results, but I include mine here in case you might find them useful. Your results may be different.

Part I: Inelastic Collisions

Here are the raw data from my inelastic equal mass measurement. (mA = mB = 0.250 kg.)

Raw Data

Here is my fit to find vA,1 for mA = mB = 0.250 kg.

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my fit to find v2 for mA = mB = 0.250 kg.

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my fit to find vA,1 for mA = 0.25 kg and mB = 0.500 kg.

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my fit to find v2 for mA = 0.25 kg and mB = 0.500 kg.

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my fit to find vA,1 for mA = 0.500 kg and mB = 0.250 kg.

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my fit to find v2 for mA = 0.500 kg and mB = 0.250 kg.

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Part II: Elastic Collisions

Here are the raw data from my elastic equal mass measurement. (mA = mB = 0.250 kg.)

Raw Data

Here is my fit to find vA,1 for mA = mB = 0.250 kg (elastic).

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my fit to find vA,2 for mA = mB = 0.250 kg (elastic).

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my impulse analysis to find vB,2 for mA = mB = 0.250 kg (elastic).

Impulse Plot

And the numerical result of the analysis:

Impulse Calculation Result

Here is my fit to find vA,1 for mA = 0.250 kg and mB = 0.750 kg (elastic).

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my fit to find vA,2 for mA = 0.250 kg and mB = 0.750 kg (elastic).

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my impulse analysis to find vB,2 for mA = 0.250 kg and mB = 0.750 kg (elastic).

Impulse Plot

And the numerical result of the analysis:

Impulse Calculation Result

These are the raw data for an elastic collision with mA = 0.750 kg and mB = 0.250 kg. If you position cart B correctly and give just the right initial velocity to cart A, you can get three collisions between the carts and cart B will collide twice with the spring. Try and see if you can get this.

Raw Data

Here is my fit to find vA,1 for mA = 0.750 kg and mB = 0.250 kg (elastic).

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my fit to find vA,2 for mA = 0.750 kg and mB = 0.250 kg (elastic).

Velocity Plot

And the numerical result of the fit:

Velocity Fit Result

Here is my impulse analysis to find vB,2 for mA = 0.750 kg and mB = 0.250 kg (elastic).

Impulse Plot

And the numerical result of the analysis:

Impulse Calculation Result

Here are my measurements of the force between two carts that results from the repulsion between the two pairs of magnets. I measured it with a pair of magnets attached to the force sensor instead of the spring, and used a different LabVIEW program called "Force Law Experiment." The purple line is a fit to an exponential function.

Magnetic Force Law

Here are the parameters from the exponential fit.

Magnetic Force Fit

Incidentally, the force between these magnets can be calculated from Maxwell's equations. It's probably beyond what will be covered in 8.02 because it involves elliptic integrals, but if the calculation is done a function results that fits very well. Here is a graph of the fit.

Current Loop Plot

If you want to see a copy of my report, click this link.

J. D. Litster, October 23, 2007.