Describing Motion and Force

Front

Motion Noun

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[moh-shun]

Back

Motion

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The process of an object changing its position over time when compared to a fixed reference point.

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Example: A basketball's path shows motion as it moves through the air into the hoop.

Front

Reference Frame Noun

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[ref-er-uhns freym]

Back

Reference Frame

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A place or object used as a point of comparison to determine if another object is in motion.

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Example: A box on a moving car shows motion relative to the car and the ground.

Front

Relative Motion Noun

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[rel-uh-tiv moh-shun]

Back

Relative Motion

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The movement of an object as observed from a specific, and potentially moving, reference frame.

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Example: Two buses moving in opposite directions show how motion is observed from different reference frames.

Front

Force Noun

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[fawrs]

Back

Force

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A push or a pull exerted on an object that can cause it to change its motion.

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Example: A person pushing a box demonstrates force as a push causing motion.

Front

Contact Force Noun

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[kon-takt fawrs]

Back

Contact Force

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A force that is applied to an object by another body that is in direct physical contact with it.

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Example: A person pushing a box shows contact force as they apply force directly to the object.

Front

Friction Noun

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[frik-shuhn]

Back

Friction

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A contact force that resists the relative motion between two surfaces that are rubbing against each other.

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Example: A box on a surface shows friction as a force opposing motion, with a zoomed-in view of the contact area.

Front

Noncontact Force Noun

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[non-kon-takt fawrs]

Back

Noncontact Force

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A force that is applied to an object by another body without the need for any physical touch.

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Example: Magnets attract or repel each other without touching, demonstrating noncontact force.

Front

Gravity Noun

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[grav-i-tee]

Back

Gravity

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A fundamental noncontact force of attraction that pulls any two objects with mass toward each other.

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Example: The image shows gravity as a force pulling two objects together, represented by arrows.

Front

Magnetism Noun

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[mag-ni-tiz-uhm]

Back

Magnetism

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A noncontact force produced by moving electric charges that can attract or repel other materials.

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Example: Magnetic field lines show how a magnet can attract or repel materials.

Front

Electrical Force Noun

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[ih-lek-tri-kuhl fawrs]

Back

Electrical Force

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A noncontact force of attraction or repulsion that exists between any two electrically charged objects.

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Example: Positive and negative charges attract, while like charges repel, demonstrating electrical force.