PURPOSE: To illustrate frictional forces in a weird way.
DESCRIPTION: The wooden figure has holes in its arms which are drilled at an angle with respect to the vertical. Strings are passed through the holes to the ends of the wooden bar at the top. Whe the strings are pulled alternately (like milking a cow) while being kept reasonably taut, the frictional force is greater for the string that is at the greater angle. The string at the lesser angle slips. The alternating frictional force causes the social climber to slowly "climb" up the strings to the top.
REFERENCES: (PIRA unavailable.)
EQUIPMENT: Social climber on stand, as photographed.
SETUP TIME: 5 min.
Go back to Lecture-Demonstration Home Page.