A lever works by helping you overcome gravities force. This is done by making use a a fulcrum.

Because some energy has to always be used to overcome friction. 100% efficiency could possibly only existence in space, because there is lack of gravity and friction.

Actual Mechanical Advantage-Determined by measuring the actual forces on a machines.

Ideal Mechanical Advantage-Is the mechanical advantage in the absence of friction.

Action and Reaction

The Scissors is using a lever and wedge and that's two simple machines in one .

Rube Goldberg (1883-1970) was a Pulitzer Prize winning cartoonist, sculptor and author.

A Rube Goldberg contraption – an elaborate set of arms, wheels, gears, handles, cups and rods, put in motion by balls, canary cages, pails, boots, bathtubs, paddles and live animals – takes a simple task and makes it extraordinarily complicated.

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