More Work!Work Input and Output quiz
In order to calculate the ME of a machine you must know the Work Input and the Work Output. To find the work input and output you multiply the force by the distance.

Work Output:

  • Useful work done by a machine (Wo)
  • The force of the object being moved multipied by the distance of which the object is being moved without the assisstance of a machine.
  • Wo < Wi
  • Expressed as a Joule

Work Input:

  • Total work done by a machine (Wi)
  • The force exerted by an operator multipied by the distance that the operator must move.
  • Wi = Wo + Wfriction
  • Expressed as a Joule

ME:

  • Expressed as a percentage (%)
  • Always less than 100%
  • Wo/Wi x 100%

For example: The lever and the ramp
me lever 2.PNG
The Lever

ME ramp.PNG
The Ramp




The lever is more efficient because there is less friction between the box and the surface that it is on. To learn more about friction click Here