Mechanical Efficiency and Simple Machines

Vocabulary flashcards covering mechanical efficiency, compound machines, levers, mechanical advantage, wheel and axle.

Mechanical Efficiency (ME)

The efficiency of a machine, ideally 100% but always less due to friction; calculated as (work output / work input) x 100.

Friction

A force that opposes motion, causing a decrease in mechanical efficiency.

Compound Machine

A machine consisting of more than one simple machine.

Lever

A simple machine that pivots around a fulcrum to multiply force or distance.

Fulcrum

The pivot point of a lever.

Mechanical Advantage (MA)

The ratio of output force to input force; a higher MA makes a task feel easier but does not decrease the amount of work done.

Wheel & Axle

A simple machine consisting of two circular objects of different sizes, where one turns the other. Increasing the size of the wheel increases distance and decreases input force.

1st Class Lever

A lever where the fulcrum is located between the input force and the output force.

2nd Class Lever

A lever where the output force is located between the input force and the fulcrum.

3rd Class Lever

A lever where the input force is located between the fulcrum and the output force.