PURPOSE: To illustrate mechanical advantage.
DESCRIPTION: The screw jack is used to lift the back end of the wagon with several people aboard. It can easily be operated with one hand, because it has a mechanical advantage of about 420 when used with a 22 inch handle.
SUGGESTIONS:
REFERENCES: (PIRA unavailable.)
EQUIPMENT: Screw jack, wood block, and wagon, as photographed.
SETUP TIME: 5 min.