1M40.64 - Spring Gun and Dart Set - Air Track & Carts

Code Number:
1M40.64
Demo Title:
Spring Gun and Dart Set - Air Track & Carts
Condition:
Good
Principle:
Spring Compressed Energy vs. Projectile Mass
Area of Study:
Mechanics
Equipment:
Dart Gun, Darts with masses of 3.5, 7, 14, and 30 grams.
Procedure:

Load the 14 g. projectile into the gun, hold at floor level, and shoot upwards observing the height obtained.  Then load the 30 g. projectile at floor level and also shot upwards.  Observe that this height is only half of the 14 g. projectile height.

An interesting variation is to use two guns.  Load one with a regular dart and the other with a massive dart.  Point them both at the ground from the same height.  Which dart will strike the ground first if both are fired at the same time.

Craig Kletzing's variation is to do this horizontally on the air track.  Use the apparatus in the picture as this will give you the most accurate measurements.  Note that the photogate is at 75 centimeters on the air track and that the 600 gram mass is one with a large magnet while the 300 gram mass is one with a small magnet.

References:
• Figuring Physics, TPT, Vol. 39, # 2, Feb. 2001, p. 74 & p. 82.
• Robert Weinstock, "Figuring the Dart Gun", TPT, Vol. 39, # 5, May 2001, p. 262.
• Borislaw Bilash II, David Maiullo, "A Darting Demo of the Second Law", A Demo a Day: A Year of Physics Demonstrations, p. 64.
• M- 288: "Dart Guns", DICK and RAE Physics Demo Notebook.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.