James Rabchuk's recent paper1 describes a method for measuring the kinetic energy changes in the Gauss accelerator, as well as a calculation of the change in potential energy. In this paper, a simple method for measuring both the change in potential energy and the change in kinetic energy will be presented. The measurements can be made with rulers, strings, and weights. In the process, your students will learn about the relationship between work and potential energy as well as the law of conservation of energy. Issues associated with the law of conservation of momentum in the accelerator will also be addressed.
REFERENCES
1.
J.
Rabchuk
, “The Gauss rifle and magnetic energy
,” Phys. Teach.
41
, 158
–161
(March 2003
).2.
This device is also known as the Gauss rifle. However, due to the high rate of gun violence in our schools, I choose to call it the Gauss accelerator.
3.
The idea of using spherical magnets came about because part of the magical properties of the Newton's cradle device is often attributed to the spherical shape of the colliding spheres. For example, see
A.
David
, “Colliding rods: Dynamics and relevance to colliding balls
,” Am. J. Phys.
62
, 522
–525
(1994
).4.
Science Toys (http://www.scitoys.com/scitoys/scitoys/magnets/gauss.html) sells a kit with cube-shaped magnets for $26. Spherical neodymium magnets can be obtained fairly cheaply from Educational Innovations Inc.; 888-912-7474 or http://www.teachersource.com.
5.
Thin brass strips of known thickness (1/64 in, 1/32 in, and 1/16 in) were used. They were found at a local hardware store and were very inexpensive.
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© 2004 American Association of Physics Teachers.
2004
American Association of Physics Teachers
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