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This animation enables you to compare the properties of a fixed pulley with those of a pulley system. One pulley enables you to change the direction in which a force acts. Associated  with one or several other pulleys (compound devices) the pulley enables one to reduce the force needed to lift a mass.

Note that the distance the mass is displaced is reduced by a factor identical to the factor of reduction of the force.  Thus, for a system with two pulleys, the force needed is halved, but the so is the height of displacement.  Energy is thus conserved.

Note: The friction and weight of the cord and the fasteners is ignored.

Select the pulley system you want to work with then click on

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  • To compare the properties of fixed pulleys and pulley systems.
  • To illustrate the usefulness of pulley systems.
  • To address the notion of energy in order to teach that it is conserved.
  • To introduce other devices that can be used to multiply forces (levers, pedals, wheels)