Free-fall in a Vacuum (Penny and Feather Demo)


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 Code Number :   1C20.10  

Disclaimer:

Reprinted by permission of Dick Berg, University of Maryland, for use on this website.

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Condition :   Good  
Principle :   Acceleration Due to Earth's Gravity is Constant  
Area of Study :  Mechanics   
Equipment :   Vacuum tube with feather & penny, Vacuum pump, book, and piece of paper.

 
Procedure :   The vacuum tube may have to be taken apart for cleaning. Check the oil in the vacuum pump and maintain at the proper level. Using the triangular variable wedge will help insure that the tube will not roll off the table.

A small ball of cotton may be substituted for the feather.

A way to do this without the vacuum system is to take a large text book and place a piece of paper directly on top of it.  When this is dropped the paper will drop at the same speed as the textbook and stay directly on top of the book.

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   Web Sites

A video of the Apollo 15 Astronauts performing this experiment on the moon is available at:


   References


Walter Connolly,  "Teaching Mechanics with a Digital Camera,"  TPT, Vol. 25, # 7, p. 445, (Oct. 1987).

 

 

 

M- 088:  "Coin and Feather in Tube,"  DICK and RAE Physics Demo Notebook.

 

 

 

Ron Hipschman, Exploratorium Cookbook III, "Falling Feather," p. 137-1 - 137-5.

 

"Falling Feather,"  Science Snackbook.

 

"397, Was Galileo Right?"  Christopher P. Jargodzki and Franklin Potter,  Mad About Physics, p. 154, 297.

 



Mail Questions and Comments to:  Dale Stille