Demonstrations

Metal Boats - Buoyancy vs Surface Area

Code Number :	2B40.28?
Disclaimer:	Reprinted by permission of Dick Berg, University of Maryland, for use on this website. The demonstrations contained and referenced herein are listed for the purposes of cataloging and describing physics demonstrations which should be conducted only under the direction of a trained instructional support professional or physicist. These demonstrations are not presented for the purpose of being conducted by persons unconnected to this Facility and/or persons not consulting with or being supervised by the recognized instructional support professional or physicist and his/her staff. The University is responsible only for those demonstrations carried out using its own equipment using established safety and scheduling policies, and bears no responsibility for those choosing to use this source material for their own purposes. All demonstrations described and contained herein are public domain, and can also be found in reference materials in libraries, bookstores, and electronic sources. Further information regarding legal liability in use of demonstrations and labs will be found on the web site Injuries in School/College Laboratories in USA. The University of Iowa Disclaimers: University of Iowa Disclaimer All Rights Reserved..
Condition :	Good
Principle :	Buoyancy
Area of Study :	Heat & Fluids
Equipment :	1 ft square Plexiglas water tank, Aluminum foil, boat mold, aluminum blocks.
Procedure :	Cut a large piece of aluminum foil and fold it in half. Press this into the boat mold and cut off the excess so that the boat is 1 to 2 inches high. Place this into the Plexiglas tank and observe how it floats. Add aluminum blocks as desired. Take the boat out of the water and crush into a small cube with a hammer. When placed back into the water this cube will sink even though it has the same mass as the original hull. A non-boat version of this is to place an ice cube in a beaker of salad oil. The ice cube will float about half way down. As it melts, it will continue to sink in the salad oil.

References

Christo Popov, "A Boat, A Stone, and Another", TPT, Vol. 34, # 6, Sept. 1996, p. 327.

Martin Gardner, "Physics Trick of the Month", "Water Level Riddle", TPT, Vol. 33, # 5, May 1995, p. 274.

Ludwik Kowalski, "How Does Stable Become Unstable", TPT, Vol. 33, # 2, Feb. 1995, p. 70.

Peter M. Hall, "The Flip Side of Buoyancy", TPT, Vol. 33, # 1, Jan. 1995, p. 7.

Marie Baehr, "Baehr Responds", TPT, Vol. 32, # 1, Jan. 1995, p. 7.

Marie Baehr, "How Stable is Stable", TPT, Vol. 32, # 8, Nov. 1994, p. 470.

R. D. Edge, "String and Stick Tape Experiments", "Battleship in the Bathtub", TPT, Vol. 28, # 7, Oct. 1990, p. 510.

Robert E. Vermillion, "How Not to Sink a Ship", TPT, Vol. 27, # 5, May 1989, p. 328.

Carl C. Fields, "Response", TPT, Vol. 27, # 5, May 1989, p. 328.

Carl Fields, "More on Wooden Boats", TPT, Vol. 25, # 7, Oct. 1987, p. 419.

Richard D. "Aaron A. Abbott" Reed, "Why Do Boats Float", TPT, Vol. 25, # 1, Jan. 1987, p. 48.

"View It", TPT, Vol. 24, # 6, Sept. 1986, p. 370.

Mail Questions and Comments to: Dale Stille