• Equilibrium of forces.
  • Equilibrium of moments.
  • Relationship between force reduction and cord travel.


  • Experiment on the equilibrium of forces and moments on a differential pulley block
  • 3 pulleys made of anodized aluminium
  • 2 sets of weights
  • Ball bearing mounted steel shaft
  • HDF Laminated Base Plate

The model demonstrates the conditions of equilibrium on a differential pulley block. Three anodized aluminium pulleys of different diameter are fitted to a shaft mounted on ball bearings. The forces act, on the one hand, directly on the peripheral of the largest pulley, on the other hand, via a loose pulley on two smaller pulleys. Easy to interchange weights permit the load to be varied such that equilibrium is obtained. The model is intended for wall mounting.