PHYSICAL SCIENCESIMPLE MACHINES

Abney Elementary

A basic machine that makes up other machines is called a simple machine.

Efficiency is how well a machine changes effort into useful work.

A lever is a bar that turns on a fixed point called a fulcrum. (Examples: pry bar, pliers, scissors, see-saw)

The effort force is the force used when you push or pull a lever.

A pulley is made up of a rope or chain and a wheel around which the rope fits.

A pulley that stays in the same place is called a fixed pulley. Fixed pulleys are often used to raise and lower something lightweight such as a flag.

Multiple pulleys are used to move heavy loads.

A wheel and axle is made up of a large wheel attached to a smaller wheel or rod.

Examples of a wheel and axle are a door knob, a fishing reel, and a wheel on a wheelchair.

Wrapping an inclined plane around a pole makes a screw

Turning a screw moves things up a spiral ramp.

An inclined plane is a flat surface that has one end higher than the other. (Example: a ramp)

The effort force of an inclined plane is applied upward along the plane.

An inclined plane makes work easier by decreasing the force needed to lift an object.

Two inclined planes placed back to back form a wedge. (Example: the blade of an ax)

A wedge pushes things apart while a ramp lifts things.

Some machines are made up of different kinds of simple machines.

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