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Penny and Feather
# 1C20.10

Description: The demo shows that, when not affected by air resistance, a "light" object (the feather) falls at the same rate as a "heavy" object (the penny).

Instructions: Shake the lead ball and feather to one end of tube. The tube is filled with air. Quickly bring the tube to a vertical position and watch the objects fall. Connect the tube to the pump. It takes a few minutes to pump air out of the tube. Close valve and disconnect from pump and repeat as with air. See Notes.

Hazards: If the feather (or "light" object) is at either end of the tube when pumped down, it can get stuck in between the stopper and the tube wall, so start pumping with falling objects away from the ends of the tube.

Parts: Penny and feather tube
Vacuum pump

Purchased/Built: purchased

Quant. in Demo Room: 1

Source: Central Scientific

Demo References
Hilton M-5a Dropping the feather and coin in a vacuum.
The Video Encyclopedia of Physics Demonstrations Disc 01-14 Metal and paper discs are placed in identical tubes.
Sutton M-79 Invert a large glass tube containing a feather and bit of lead.

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