Simple Macines

Simple machines are machines that change the force, distance, or strength of an object.

Parts of Simple Machines

  • Effort
    • The force applied to the simple machine
  • Output
    • The force that a machine supplies
  • Load
    • The object moved by the output
  • Effort Arm
    • The part of the simple machine that receives the effort
  • Resistance Arm
    • The part of the simple machine that delivers the output

Different Simple Machines

The Lever

The lever consists of a fulcrum. The fulcrum is the point at which a bar rotates on.

  • First Class Levers
    • In this lever, the fulcrum is in the middle of the bar
    • The effort and the output are on the opposite sides of the fulcrum.
    • The effort arm and resistance arm are on
  • Second Class Levers
    • The fulcrum is at the edge of the bar.
    • The output and the effort are on the same side, and the output is larger than the effort.
  • Third Class Levers
    • Both arms are on the same side of the fulcrum
    • Resistance arm is longer than effort arm
    • Output is less than effort
    • Tweezers are two third class levers put together.


A pulley is a rope running across a wheel. On one side of the rope, the pull is made to lift up the load on the other side.

Wheel and axle

A wheel is a round object that can roll. When this is put through an axle, it can be attached to anything such as a vehicle. The axle acts like the effort and resistance arm while the wheel acts like the fulcrum.

Inclined Planes

An inclined plane is a type of simple machine that slopes downward. A ramp is an inclined plane.


A wedge is an inclined plane that slopes to make a sharp edge. An example of this is an ax.

When you wrap an inclined plane around a wedge, you make a screw.


What are Compound Machines?

A compound machine is when more than one machines are combined in an object. An example of this is a tow-truck. A tow-truck has a lever, pulley, wheel and axle, and a wedge.


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