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Simple Machines

6 Simple Machines

Six Simple Machines

  1. Pulley
  2. Wedge
  3. Wheel and Axle
  4. Lever
  5. Inclined Plane
  6. Screw



A wheel with a grooved rim in which a rope can run and so change the direction of a pull. It is a simple machine that is used to raise weights.



A piece of wood or metal tapering to a thin edge, used in splitting or separating.

Wheel and Axle


Axle on which a wheel is fastened, used to lift weights by winding a rope onto the axle as the wheel is turned.



A bar which turns on a fixed support called a fulcrum and is used to transmit effort and motion.

3 Classes of Levers

  • First-Class Lever
  • Second-Class Lever
  • Third-Class Lever

First-Class Lever

  • The fulcrum is between the effort and the resistance
  • Motion in direction opposite effort

Second-Class Lever

  • Resistance between effort and fulcrum
  • Motion in same direction as effort

Third-Class Lever

  • Effort between resistance and fulcrum
  • Motion in same direction as effort.

Inclined Plane


Plank or other plane surface set at an acute angle to a horizontal surface.



A cylinder with an inclined plane wrapped around it and fitting into a threaded cylindrical hole. Screws are used in jacks to lift heavy loads.

Vocabulary Terms
  1. Pulley
  2. Wedge
  3. Wheel and Axle
  4. Lever
  5. First-Class Lever
  6. Second-Class Lever
  7. Third-Class Lever
  8. Inclined Plane
  9. Screw
Review Questions
Related Internet Links