Machines

Front

Machine Noun

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[muh-sheen]

Back

Machine

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A device that makes tasks easier by changing the magnitude or direction of an applied force to transfer energy.

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Example: This diagram shows pulley systems, a type of simple machine, using ropes and wheels to lift a heavy weight (W) with less effort (F).

Front

Work Noun

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[wurk]

Back

Work

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The transfer of energy that occurs when a force is applied to an object that moves in the force's direction.

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Example: This image shows work being done, as a person applies a force (the push) to move an object (the box) over a distance.

Front

Input Work (Wi) Noun

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[in-poot wurk]

Back

Input Work (Wi)

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The work done on a machine by the user, calculated as the effort force multiplied by the effort distance.

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Example: Applying an effort force with your hand over a distance on a lever is the input work, which makes it easier to lift the load.

Front

Output Work (Wo) Noun

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[out-poot wurk]

Back

Output Work (Wo)

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The work done by a machine on an object, which is the product of the resistance force and resistance distance.

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Example: This diagram shows a pulley system, a simple machine, doing work on a 100 lb load. The output work is the work done by the pulley on the load.

Front

Effort Force (Fe) Noun

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[ef-ert fors]

Back

Effort Force (Fe)

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The force exerted by a user on a machine to make it operate, also known as the input force.

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Example: This diagram shows that effort force is the push or pull applied to a simple machine, like a lever, to overcome a resistance force.

Front

Resistance Force (Fr) Noun

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[ri-zis-tuhns fors]

Back

Resistance Force (Fr)

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The force exerted by a machine to overcome resistance, such as the weight of an object being lifted.

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Example: As the cart moves forward, the rough surface creates a resistance force called friction, which pushes in the opposite direction of the cart's motion.

Front

Mechanical Advantage (MA) Noun

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[muh-kan-i-kuhl ad-van-tij]

Back

Mechanical Advantage (MA)

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A measure of force amplification, calculated as the ratio of the resistance force to the effort force (Fr/Fe).

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Example: This diagram shows a lever, a simple machine. Applying a smaller input force over a long effort arm moves a heavier object with a larger output force over a short resistant arm, creating mechanical advantage.

Front

Ideal Machine Noun

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[ahy-deel muh-sheen]

Back

Ideal Machine

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A hypothetical machine with 100% efficiency, where input work is perfectly converted into useful output work without losses.

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Example: This diagram shows that for an ideal machine like a pulley system, the Ideal Mechanical Advantage (IMA) is equal to the number of ropes (N) supporting the load.

Front

Ideal Mechanical Advantage (IMA) Noun

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[ahy-deel muh-kan-i-kuhl ad-van-tij]

Back

Ideal Mechanical Advantage (IMA)

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The theoretical mechanical advantage of a frictionless machine, calculated as the ratio of effort distance to resistance distance.

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Example: This image shows how a crowbar acts as a lever, connecting a real-world example to a diagram that defines Ideal Mechanical Advantage (IMA) as the ratio of the effort arm length (Le) to the resistance arm length (Lr).

Front

Efficiency Noun

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[ih-fish-uhn-see]

Back

Efficiency

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The ratio of a machine's useful output work to its total input work, typically expressed as a percentage.

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Example: This diagram shows that when a machine uses fuel for power, only some of that energy becomes useful output, while the rest is lost as waste heat.