Set up for Light the Match demo
Parabolic mirror with match holder assembly
Parabolic mirror with heater coil assembly
Set up for Light the Match demo

 

Code Number: 4B40.10

Demo Title: Light the Match

Condition: Good

Principle: Radiation, Reflection, and Focusing of Heat

Area of Study: Thermodynamics

Equipment: 

Parabolic mirror with match holder assembly, Parabolic mirror with heater coil assembly, and Variac.

Procedure:

Place the parabolic mirrors on rods at each end of the table. Use the rod attached to mirror with the match holder and adjust both mirrors to the same height. Make sure they are as parallel to each other as you can eyeball it, (doesn't need to be measurement accurate). Turn the Variac all the way up and wait 45 seconds. At about 30 seconds the match will start to visibly smoke and will burst into flames at about 45 seconds.

If precise alignment is necessary, you may use a radiometer as the detector to find and fine tune the focal point.

References:

  • Richard E. Berg, "Heat-Wave Focusing by Concave Reflectors", TPT, Vol. 28, # 1, Jan. 1990, p. 56.
  • Thomas B. Greenslade, Jr., "19th Century Textbook Illustrations XXX - Demonstrations of Thermal Radiation", TPT, Vol. 17, # 5, May 1979, p. 320.
  • James Evans and Brian Popp, "Pictet's Experiment: The Apparent Radiation and Reflection of Cold", AJP, Vol. 53, #8, Aug. 1985, p. 737.
  • Julien Clinton Sprott, Physics Demonstrations,  "2.14",  p. 101, ISBN 0-299-21580-6.
  • J. Klinger Scientific Apparatus, "Infrared Radiation", Experiments in Optics, Part 1, #14.
  • W. Bolton, "The Efficiency of Reflectors on Electric Fires", Book 2 - Waves and Particles, Physics Experiments and Projects, 1968, p. 86.
  • Joseph Frick, "# 372 & 373 - For Remaining Experiments in Radiant Heat", Physical Technics: Or Practical Instructions for Making Experiments in Physics and the Construction of Physical Apparatus with the Most Limmited Means, p. 447.
  • "Reflectors, etc., For Radiation of Heat", Pike's Illustrated Catalogue of Scientific & Medical Instruments, Pike's Illustrated Descriptive Catalogue of Optical, Mathematical, and Philosophical Instruments, 1984, p. 98.
  • The Queen Catalogues Vol. II, Catalogue of Physical Instruments, No. 4931, p. 60.
University of Maryland Physics Department QOTW Question #148
University of Maryland Physics Department QOTW Answer #148
 
4B40.10 - Light the Match