PURPOSE: To illustrate addition of forces.
DESCRIPTION: Case 1: Equilibrium is attained between the downward force of gravity on the central mass and forces exerted at arbitrary angles along two strings. Angles and forces may be independently varied.
Case 2: Equilibrium is attained betwen the downward force of gravity and the upward forces at the ends of the weighted bar. Forces at the ends of the bar and at any point along the bar are independently variable.
SUGGESTIONS: Shadow projection available on request.
REFERENCES: (PIRA unavailable.)
EQUIPMENT: Two pulleys, weights, and bar, as photographed.
SETUP TIME: 5 min.
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