In a system of parallel forces at equilibrium the sum of the counterclockwise torques is equal to the sum of the counterclockwise direction.
The mass of a meter stick and the mass of a weight were measured and recorded. Then an axil was attached that allowed the meterstick to placed on a stand. The position of the fulcrum was adjusted until the meter stick was horizontally balanced on the stand. The location of the fulcrum was then recorde. next we changed the location of the fulcrum to 60 cm and placed the weight over the shorter side. The distance of the weight from the fulcrum was then adjusted until the meter stick was horizontally balanced. The new position of the fulcrum was then recorded.
Meterstick CG: 49.9cm
Meterstick mass: 39.3g
Meterstick weight (hundredth of a Newton): .91N
Equilibrium position of unknown mass: 79.9cm
Unknown mass: 47.5g
Unknown weight: (hundredth of a Newton): .47N
(.46 - .47) / .47 = -.02 = 2% Error
We found within 2% error that the sum parallel forces at equilibrium is equal to the sum of the counterclockwise torques is equal to the sum of the counterclockwise direction within a system.