Picturing Motion

Front

Motion Noun

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[moh-shuhn]

Back

Motion

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The phenomenon in which an object's position changes over time, observed as a continuous alteration of its location.

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Example: This diagram shows an object (a cyclist) changing its position over time, which is the definition of motion. The arrows indicate the path of movement.

Front

Position Noun

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[puh-zish-uhn]

Back

Position

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The specific location of an object in space, which must be known to describe its movement relative to a reference.

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Example: This diagram shows an object's position, which is its specific location on a number line. The person's initial position is -2 (X₁).

Front

Straight-line motion Noun

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[streyt-lahyn moh-shuhn]

Back

Straight-line motion

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Movement that follows a direct path between two points without any turning, representing the simplest form of displacement.

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Example: A car is shown moving in one direction along a straight path, which is a clear example of straight-line motion.

Front

Motion diagram Noun

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[moh-shuhn dahy-uh-gram]

Back

Motion diagram

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A series of images showing the positions of a moving object at equal and consecutive time intervals to visualize motion.

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Example: This diagram shows an object's position at equal time intervals. Closely spaced dots (top) mean slow constant speed; widely spaced dots (bottom) mean fast constant speed.

Front

Particle model Noun

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[pahr-ti-kuhl mod-l]

Back

Particle model

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A simplified representation of a moving object where the object is replaced by a single point to analyze its motion.

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Example: This image shows how the particle model explains states of matter: particles in a solid are tightly packed, in a liquid they can slide past each other, and in a gas they move freely.