This paper describes the use of laser pulse photography, optical timing, and pulsed Schlieren to look more closely at the dynamics of a popular lecture demonstration—the so-called “Ping-Pong cannon” or “vacuum bazooka.”1,2 These optical diagnostic techniques are applied to two types of cannons and lead to greater knowledge of the kinematics of the accelerating ball, along with some details of the exit mechanism and subsequent target interactions.
REFERENCES
1.
John
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41
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–247
(April 2003
).2.
Eric
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and Louis
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(July 2004
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New Focus, Large-Area Photoreceiver, Model #2031.
4.
Stanford Research Systems Inc., Model #DG535.
5.
Canon EOS 10D, w/100-mm macro lens.
6.
David Falk, Dieter Brill, and David Stork, Seeing the Light (Wiley, New York, 1986), pp. 172–174, or Eugene Hecht, Optics, 4th ed. (Addison-Wesley, Reading, MA, 2001), pp. 621–623.
7.
Edmund Industrial Optics, 6-in Schlieren System #R71-013.
8.
H.W. Liepman and A. Roshko, Elements of Gasdynamics (Wiley, New York, 1957).
9.
H. McMahon, J. Jagoda, N. Komerath, and J. Seitzman, “Transient measurements in a shock tube,” AE3051 Experimental Fluid Dynamics (Georgia Tech School of Aerospace Engineering, 1999). See lab directions at: http://www.ae.gatech.edu/classes/ae3051/AE3051Labshocktube.pdf.
10.
Private communication, David F. Davidson and Jay B. Jeffries, Stanford University, High Temperature Gasdynamics Laboratory.
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© 2005 American Association of Physics Teachers.
2005
American Association of Physics Teachers
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