1K20.14 - Variable Friction - Dynamics Track or Air Track
The dynamics track can be either level of inclined for this demonstration. Set the desired amount of friction on the cart by turning the large screw. Pulleys, masses, and an interface with sensors may also be used for this demonstration.
Set the desired screen on a car and give it a push on a level air track. The car will visibly slow down if the screen is big enough, or you can measure the velocity of the car with a sonic sensor. A couple of photogates may also be used to take velocity measurements of the car at several points during its run.
- Michele D'Anna, Tommaso Corridoni, "Magnetic Force from Terminal Velocity", TPT, Vol. 58, #9, Dec. 2020, p. 642.
- Nuri Balta, "Oscillations of a Meterstick on Two Rotating Shafts", TPT, Vol. 54, #3, Mar. 2016, p. 145.
- Joseph C. Amato and Roger E. Williams, "Turning a Common Lab Exercise into a Challenging Lab Experiment: Revisiting the Cart on an Inclined Track", TPT, Vol. 48, #5, May 2010, p. 322.
- Martin Kamela, "An Oscillating System with Sliding Friction", TPT, Vol. 45, #2, Feb. 2007, p. 110.
- Roger F. Larson, "Measuring the Coefficient of Friction of A Low-Friction Cart", TPT, Vol. 36 #8, Nov. 1998, p. 464.
- Robert P. Barrett, "The Author Replies", TPT, Vol. 13, #2, Feb. 1975, p. 68.
- John Kwasnoski, "Average Friction and Average Velocity", TPT, Vol. 13, #2, Feb. 1975, p. 68.
- Robert P. Barrett, "Friction on the Air Track", TPT, Vol. 12, #5, May 1974, p. 297.
- Peter F. Hinrichsen, "The Toppling of a Uniform Rectangular Block", AJP, Vol. 89, #11, Nov. 2021, p. 1026.
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