PURPOSE: To illustrate the center of mass in a surprising way.

DESCRIPTION: Q: How can you hang the hammer from the loop on the bottom of the hinged board so that the board will stick straight out horizontally? A: Insert the handle into the loop so that the head of the hammer is pointing back toward the hinge.

Click your mouse on the picture above to see the solution.

SUGGESTIONS: Let the students try it for a while before helping them to determine a solution.

See Question of the Week #112 for information on using this demonstration to enhance class involvement.

REFERENCES: (PIRA unknown.)

EQUIPMENT: Hinged stick with clamp to attach to table, hammer, as photographed.

SETUP TIME: None.