Homer figure on an air track car
Bart Simpson figure on an air track car
mouse figure on an air track

 

Code Number: 1F30.25

Demo Title: Inertia of Motion - Air Track & Homer

Condition: Excellent

Principle: Inertia of Motion

Area of Study: Mechanics

Equipment: 

Air track, platform car, passengers for car

Procedure:

Place one of the passengers on the air track platform cart.  Push them toward one end of the air track.  When the cart hits the end of the air track, the cart will bounce back, but the passenger (Homer or Bart) will continue in the initial direction, fly off the cart and over the end of the air track.  You can show the effect of a seat belt by using one of the cars with a flag.  Put a rubber band around Homer and the flag so he will not fly away when the car hits the end of the air track.  

A variation of this is to use one of the jumping passengers.  As long as the cart is moving uniformly, the figure will jump up and down while remaining on the cart.  When the cart hits the end of the air track, the figure will fly off the cart and over the end of the air track in the same manner as the above example.

References:

  • John Wolbeck, "Instantaneous Velocity Using Photogate Timers", TPT, Vol. 48, # 4, April 2010, p. 262.
  • "Figuring Physics", TPT, Vol. 46, # 9, Dec. 2008, p. 552.
  • Mark A. Ilyes and James M. Filizzi, "Pizza Boy vs the Highway Department", TPT, Vol. 43, No. 7, pp. 434-437, October 2005.
  • A. Maksymowics, W. J. Renoud, "Car Safety Demonstrations for Air Track", AJP, Vol. 41, #11, p. 1294
  • Jodi and Roy McCullough, "Vectors with a Pop Over Toy", The Role of Toys in Teaching Physics, p. 4.98.
  • Borislaw Bilash II, David Maiullo, "Friction is Working", A Demo a Day: A Year of Physics Demonstrations, p. 80.
  • Borislaw Bilash II, David Maiullo, "It's All Relative", A Demo a Day: A Year of Physics Demonstrations, p. 16.
  • Mercer, "Crash Test Dummy", Junk Drawer Physics, p. 11.