Wheel and axle
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The wheel and axle is a variation of a lever it is basically a lever shaped in a circle. The fulcrum is in the middle of the wheel and it rotates around. The Wheel helps extend the force of a lever but in 360 degrees. The wheel also is important for reducing friction on an object. For example in a car there would be a lot more friction if it did not have wheels. The wheel and axle is also part of a pulley.



Pulley
A pulley is a rope with a heavy object tied to it being pulled around a wheel and axle and it is part of the lever family. The pulley is very efficient with almost no friction and it help bring a smaller load over a longer distance not much unlike an inclined plane. There can also be two or more pulleys on one rope which would use less force over an even longer distance
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