Experiment Two.

This experiment demosntrates F = MA by applying a constant force to a friction free mass.    

The following parts are needed:

1)  A length of HO gague railroad track .

2)  A HO gague railroad car.  Hobby stores carry both the track and the car.

3)  A very large bolt.  I used a 3/4 x 8 inch bolt from a Home Depot.

4)  A length of thin elastic cord.    I brought mine at the local Wall mart.  

The parts are shown below:


  The car is then placed on the section of track and the bolt is added to provide mass.    To apply a force the elastic cord is attached to the car and streched to a point where it can be tied off.    The longer the cord is the more uniform the force is so it is good if the cord can run into another room ( or even two).   



When the car is released it starts off slowley and then accelerates.   The important thing to realize is that the elastic does not cause the car to simply move.  It causes the cart to accelerate.    That meanes that the car will continue to move faster and faster.    

moving car


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