Acceleration

Front

Acceleration Noun

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[ak-sel-uh-rey-shuhn]

Back

Acceleration

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The rate at which an object's velocity changes over time, which can involve a change in speed or direction.

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Example: A car slowing down for a speed hump is an example of acceleration, specifically deceleration, which is a change in the car's velocity.

Front

Uniform Motion Noun

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[yoo-nuh-fawrm moh-shuhn]

Back

Uniform Motion

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Motion of an object along a straight line with a constant, unchanging velocity, resulting in zero acceleration.

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Example: This distance-time graph shows a straight line, indicating that an object covers equal distances in equal intervals of time, which defines uniform motion (constant speed).

Front

Nonuniform Motion Noun

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[non-yoo-nuh-fawrm moh-shuhn]

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Nonuniform Motion

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Motion in which an object's velocity is changing, meaning its speed, direction of motion, or both are not constant.

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Example: When the car suddenly stops, its velocity changes, which is a type of nonuniform motion. The box continues to move forward because it resists this change.

Front

Velocity Noun

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[vuh-los-i-tee]

Back

Velocity

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A vector quantity that describes the rate of change of an object's position, indicating both its speed and direction.

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Example: This diagram shows a car moving at a constant velocity (20 m.p.h. in one direction), which means its acceleration is zero.

Front

Velocity Vector Noun

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[vuh-los-i-tee vek-ter]

Back

Velocity Vector

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An arrow used in a motion diagram whose length and direction represent the velocity of an object at a specific time.

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Example: This diagram shows that a velocity vector has two parts: its length represents an object's speed (magnitude), and the direction it points shows its direction of motion.

Front

Acceleration Vector Noun

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[ak-sel-uh-rey-shuhn vek-ter]

Back

Acceleration Vector

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An arrow in a motion diagram representing the magnitude and direction of the change in an object's velocity.

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Example: A falling apple speeds up due to gravity. The black arrow represents the acceleration vector, showing the direction (downward) and magnitude of this change in velocity.

Front

Velocity-Time Graph Noun

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[vuh-los-i-tee tahym graf]

Back

Velocity-Time Graph

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A graph that plots an object's velocity on the vertical axis against time on the horizontal axis to show motion.

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Example: On a velocity-time graph, the line's slope shows acceleration. An upward slope is positive acceleration, a flat line is zero, and a downward slope is negative.

Front

Constant Acceleration Noun

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[kon-stuhnt ak-sel-uh-rey-shuhn]

Back

Constant Acceleration

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A state of motion where the velocity of an object changes by an equal amount in every equal time period.

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Example: This diagram shows a car increasing its speed by the same amount (10 m/s) every second, which is the definition of constant acceleration.

Front

Average Acceleration Noun

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[av-er-ij ak-sel-uh-rey-shuhn]

Back

Average Acceleration

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The total change in an object's velocity during a measurable time interval, divided by that specific time interval.

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Example: A car increases its speed from 20 m/s to 32 m/s over 3 seconds, showing a change in velocity over time, which is average acceleration.

Front

Instantaneous Acceleration Noun

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[in-stuhn-tey-nee-uhs ak-sel-uh-rey-shuhn]

Back

Instantaneous Acceleration

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The change in an object's velocity at a single, specific instant in time, represented by the slope of a tangent line.

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Example: This velocity-time graph shows that instantaneous acceleration is the slope (steepness) of the tangent line at a single point in time.