Simple Machines

Simple machines are basic machines that are the basis for all other forms of machines.

There are six types of simple machines: 1. Simple Lever 2. Pulley 3. Wheel and Axle 4. Inclined Plane 5. Wedge 6. Screw

Simple Machines

Simple machines are divided into 2 families Lever Family

Simple Lever Pulley Wheel and Axle

Inclined Plane Family Simple Inclined Plane Wedge Screw

The Lever Family

All levers have a rigid arm that turns around a point called the fulcrum.

Levers are divided into three classes depending on the location of the fulcrum, input force, and output force.

First Class Levers

The fulcrum is located between the points of application of the input and output forces.

Example- Claw Hammer

Second Class Levers

The fulcrum is at one end of the arm, and the input force is applied at the other end.

Example- Wheelbarrow

Third Class Levers

The fulcrum is located at one end of the arm, and the output is found at the other end.

Example- Biceps

Pulleys

Pulleys are levers. The middle of the pulley is the fulcrum. The rest of the pulley acts like a first class lever.

Wheel and Axle

The steering wheel of a car is a lever. It’s made of a pulley (wheel) attached to a shaft (axle).

Inclined Plane Family

Pushing an object up an inclined plane requires less input force than lifting the same object does.

Pushing an object up a long gradual ramp requires less force than pushing up a short steep ramp.

Wedge

A wedge turns a downward force into two forces directed out to the sides.

An ax blade or a wedge pushes through and breaks apart the wood.

Screw

A screw is an inclined plane wrapped around a cylinder.

Tightening a screw with threads requires small force to act over a long distance.

Compound Machines

A machine that uses more than one simple machine.

A pair of scissors uses 2 first class levers joined at a fulcrum. Each arm has a wedge that cuts the paper.