BANGOR, Maine (WABI) - Kirsten Hibbard of the Challenger Learning Center gave us a demonstration that could keep the kids engaged during the holidays.
Fabric without a seam / heavy table top objects [non-glass] / flat smooth surface.
How to do the table cloth trick: Place a smooth piece of cloth on the flat smooth surface. Preferably, the cloth does not have a seam along the edge. [Slippery cloths works best—example a terry cloth towel is not a good choice] First practice pulling the cloth out [not down] in one swift motion. Do not hesitate and practice more than once. Next, place various objects [cups, plates, bowls, and utensils] that would be found on a table on top of the cloth, or table cloth. Good objects to use are heavy, not glass, and safe to drop. Finally, when the “table” objects are set- quickly pull the cloth out. What happened to the objects that were once on top of the cloth?
The science [credit: http://www.scientificamerican.com/article/gravity-bring-science-home/]:
This trick isn’t a trick at all! It is a demonstration of Sir Isaac Newton’s First Law of Motion. The swift motion of the cloth overcomes the resistance of friction between the cloth and the objects. The silverware then demonstrates inertia. The objects remain at rest, and gravity pulls them down to basically their original locations. The objects stay at rest until acted on by another force---GRAVITY!!!
This activity ties into the Challenger Learning Center of Maine: Challenger holds April Vacation Day STEM camps filled with physics, math, engineering and LEGOS! Summer Camp is also now open-- use the website to register. FMI- www.astronaut.org