# Mrs. Wharton’s Science Class

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Mrs. Wharton’s Science Class
Simple Machines Mrs. Wharton’s Science Class

Machines Change the amount of force you exert or the distance over which you exert the force. The idea mechanical machine would have an efficiency of 100%

Mechanical Advantage The number of times a machine increases the force exerted on the machine.

Simple Machines Inclined Plane (ramp) Wedge (ax, Incisor)
Screw (light bulb) Lever ( see-saw, wheel barrel, body joints) Pulley (window blinds, flag pole) Wheel and Axel (cars, bicycles)

Compound Machines A combination of 2 or more simple machines. Bicycle
Scissors

Inclined Plane A flat, slanted surface
You can determine the ideal mechanical advantage of an inclined plane by dividing the length of the incline by it’s height.

Wedge A device that is thick on one end and thin on the other.
You can determine the ideal mechanical advantage of a wedge by dividing the length of the wedge by it’s width.

Lever A rigid bar that is free to pivot, or rotate around a fixed point. The fixed point the lever rotates around is called a fulcrum The ideal mechanical advantage of a lever is determined by dividing the distance from the fulcrum to the input force by the distance from the fulcrum to the output force.

Screw Can be thought of an inclined plane wrapped around a central cylinder, forming a spiral. The ideal mechanical advantage of a screw is the length around the threads divided by the length of the screw.

Wheel and Axel A simple machine made up of two circular objects that are fastened together and that rotate around a common axis. You can find the ideal mechanical advantage by dividing the radius of the wheel by the radius of the axle.

Pulley Consists of a rope and cable that is wrapped around a grooved wheel. A pulley that you attached to a structure is called an fixed pulley If you are moving an object with a pulley you are using a movable pulley. The ideal mechanical advantage of a pulley is equal to the number of sections of rope that support the object.