The Wheel and Axle
The wheel and axle is a modification of the pulley in which the center pin (axle) is attached to the wheel.  Turning the wheel through a long distance with a weak force turns the axle through a shorter distance with a strong force.  Alternately, one can turn the axle with a strong force through a short distance and get the wheel to turn farther with a weak force.
 

Examples of wheels and axles:


©2001 Jeff Goodman

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