Position-Time Graphs

Front

Position-Time Graph Noun

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[puh-zish-un tahym graf]

Back

Position-Time Graph

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A graph representing an object's motion by plotting position on the vertical axis and time on the horizontal axis.

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Example: This graph shows an object's position changing over time. The straight, upward-sloping line indicates the object is moving at a constant, positive speed.

Front

Motion Diagram Noun

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[moh-shun dahy-uh-gram]

Back

Motion Diagram

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A simplified representation showing an object's position at various, often equally spaced, moments in time.

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Example: This diagram shows an object's position at equal time intervals (0, 1, 2...). The increasing space between dots indicates the object is accelerating.

Front

Position Noun

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[puh-zish-un]

Back

Position

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The specific location of an object relative to a defined origin or reference point in a coordinate system.

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Example: This image shows that position is a specific location on a reference frame, like a number line. To plot a position-time graph, you must first locate the position value on an axis.

Front

Origin Noun

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[or-i-jin]

Back

Origin

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A fixed reference point, designated as zero, from which all positions are measured in a coordinate system.

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Example: This graph shows the origin, which is the starting point where the x-axis and y-axis intersect, at the coordinates (0, 0).

Front

Best-fit line Noun

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[best fit lahyn]

Back

Best-fit line

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A straight line drawn on a graph that best represents the general trend of a set of data points.

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Example: This graph shows scattered data points and a straight line of best fit that represents the general trend, showing how an object's velocity changes over time.

Front

Instantaneous position Noun

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[in-stun-tey-nee-uhs puh-zish-un]

Back

Instantaneous position

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The position of an object at a single, specific moment or instant in time, represented by a point.

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Example: This graph shows an object's position over time. The point p1 represents the object's exact location (its instantaneous position) at a specific moment in time.

Front

Displacement Noun

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[dis-pleys-muhnt]

Back

Displacement

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The change in an object's position from its starting point to its ending point, including both magnitude and direction.

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Example: A person moves from an initial position (x₀) to a final position (x_f), and the displacement (Δx) is the direct change in position from start to finish.

Front

Intersection Noun

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[in-ter-sek-shun]

Back

Intersection

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The point where two lines cross on a position-time graph, indicating objects are at the same position simultaneously.

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Example: This graph shows two lines crossing at a single point. In a position-time graph, this intersection represents the exact moment two objects are at the same position.

Front

Slope Noun

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[slohp]

Back

Slope

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The measure of a line's steepness on a graph; on a position-time graph, it represents the object's velocity.

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Example: This position-time graph shows that slope is calculated by 'rise' (change in position) divided by 'run' (change in time), which represents velocity.

Front

Velocity Noun

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[vuh-los-i-tee]

Back

Velocity

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The rate of change of an object's position with respect to time; a vector quantity with speed and direction.

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Example: This diagram shows that velocity is a vector, meaning it has both a magnitude (its length, representing speed) and a specific direction (where it's pointing).