On This Page
Overview
Simple machines are basic devices that make mechanical tasks easier by changing force, distance, direction, or motion. Traditional simple machines include the lever, wheel and axle, pulley, inclined plane, wedge, and screw.
Lever
A lever is a rigid bar that rotates around a fulcrum. It can multiply force, increase motion distance, or change force direction depending on the placement of load, effort, and fulcrum.
Wheel and Axle
A wheel and axle consists of a larger wheel attached to a smaller axle so they rotate together. It can multiply force or increase speed depending on where input is applied.
Pulley
A pulley uses a wheel and rope or cable to change force direction or provide mechanical advantage. Pulley systems can reduce the effort needed to lift loads.
Inclined Plane
An inclined plane is a sloped surface that allows a load to be raised with a smaller force over a longer distance.
Wedge
A wedge is a moving inclined plane used to split, cut, or separate material. Knives, axes, chisels, and nails are examples.
Screw
A screw is an inclined plane wrapped around a cylinder. It converts rotational motion into linear motion and can produce large force over a small distance.
Mechanical Advantage
Simple machines are often evaluated by mechanical advantage, which compares output force to input force.
Common Mistakes
A common mistake is thinking simple machines reduce total work in an ideal system. They reduce force by increasing distance or changing direction.
Why This Matters in Physics
Simple machines connect classroom mechanics to tools, construction, transportation, manufacturing, and everyday mechanical systems.