Name: Dan Dreyfuss
Institution: The
Ethel Walker School
Address: 230
Bushy Hill Rd
Simsbury,
CT
06070
E-mail: daniel_dreyfuss@ethelwalker.org
Apparatus Title:
Variable Center of Gravity Tube
Abstract (50-75 words)
Students are shown a tube that when
placed on the edge of a table balances, not surprisingly, in the middle. The presenter picks up the tube and explains
what the center of gravity is and why, of course, the tube balances in the
middle. But when the tube is placed on
the edge of the table again, it does not balance in the center. What happened and how?
Equipment and costs
required to construct apparatus:
|
Item |
Source |
Part number |
Cost |
|
tube |
staples |
|
2.25 |
|
hardware |
Hardware store |
|
8.00 |
|
|
|
|
|
Total Cost |
10.25 |
||
Description:
A dowel rod (DR)is threaded through a
mailing tube. Washers are stacked and
taped together to make a mass with a hole in it. A rubber gasket is placed half way down on the DR to prevent the
mass form sliding beyond that point.
The mass is threaded onto the DR and the mailing tube capped. Holes
permitting the DR to exit the tube are placed in both tube caps. After the DR is set, nuts are placed on the
ends of the DR to hold it in place.
Sketch(es) (computer generated if possible):