Equilibrium Of Forces - Board Background
To demonstrate equilibrium of forces.
Three spring scales with connecting arms mounted on board on rolling cart, 1.5 kg mass, protractor.
Three forces are set up in static equilibrium. The lower spring scale is modified so that it measures its own weight plus the weight hanging on the hook below. Upper spring scales are calibrated to read zero when the connecting arms are the lower scale is removed. A large protractor can be used to measure angles directly.
(PIRA 1J30.50) See also Demonstration B2-13.