Physics Demo Number: 013		Approximate Run Time: 3 min
Free Fall Alternatives to Guinea and Feather Tube
Demo Description Instead of using the old Garland Guinea and Feather Tube one may drop the book in the Kit and the piece of paper in the Kit, separately and then together. to illustrate the same concepts.		Scientific Principles · Objects fall at same rate, independent of mass, if friction can be minimized.
Equipment · Old chemistry texbook. · Piece of Printer Paper cut down to less than size of the book	Equipment Location · Kit (013) on [F-3-4].
Instructions Note: See demo198 for new version of coin and feather tube. The Garland Tube has been returned to the cases for safekeeping, and should be regarded as unavailable for routine demos. The following comments indicate why the tube is retired, but the last comment gives a suggested live alternative. The photo shows the tube (GFT) used with the vacuum pump (VP) to show that light objects can fall at about the same rate as heavy ones if air friction can be minimized. It turns out that feathers don’t survive long in the tube. Since the tube belongs to the Garland Collection we don’t want to be disassembling it unless absolutely necessary. Hence, some scraps of plastic and fabric have replaced the feather. No Guinea was available the last time the end cap was removed and sealed with silicone. The silicone is probably fairly high-tech for such a venerable old piece of equipment, but we have never found a modern tube that works as well. The visibility of the whole demo from very far back in the lecture hall is very questionable. Hence one might consider showing a videotape of an astronaut dropping a hammer and feather on the moon and on the earth instead of putting the Garland Collection piece at risk. The practical alternative for a live demo is, of course, to drop a piece of paper and a book separately and then together with the paper on top of the book. Writeup created by David A. Burba Copyright © 2014, Vanderbilt University.   All Rights Reserved.