Distance and Displacement

Front

Motion Noun

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[moh-shun]

Back

Motion

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A change in an object's position over time relative to a specific reference point.

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Example: This image shows a runner with arrows representing the forces, like gravity and ground reaction, that cause an object to be in motion.

Front

Reference Point Noun

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[ref-er-uhns point]

Back

Reference Point

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A stationary place or object used for comparison to determine if another object is in motion.

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Example: The house, labeled 'Home,' acts as a fixed reference point. The car's motion and position on its way to school are measured relative to this starting point.

Front

Frame of Reference Noun

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[freym uhv ref-er-uhns]

Back

Frame of Reference

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A system of objects that are not moving with respect to one another, used to describe motion.

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Example: The measured speed of an object depends on the observer's frame of reference. A ball moving at 3 m/s on a walkway appears to move at 4 m/s from the ground.

Front

Inertial Reference Frame Noun

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[in-ur-shuhl ref-er-uhns freym]

Back

Inertial Reference Frame

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A coordinate system or frame of reference that is either at rest or moving with a constant velocity.

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Example: From the boy's viewpoint (his reference frame), the woman is moving. From the woman's viewpoint (her reference frame), she is still. Motion is relative.

Front

Scalar Noun

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[skey-ler]

Back

Scalar

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A physical quantity that is fully described by its magnitude or numerical value alone, without any direction.

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Example: A speedometer shows a car's speed, such as 300 km/h. This is a scalar quantity because it only has a magnitude (a number) and no direction.

Front

Vector Noun

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[vek-ter]

Back

Vector

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A physical quantity that is described by having both a magnitude and a specific direction.

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Example: This image shows that a vector is a quantity represented by an arrow, which has both a specific length (magnitude) and a direction.

Front

Magnitude Noun

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[mag-ni-tood]

Back

Magnitude

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The size, amount, or length of a quantity, often represented by a numerical value.

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Example: This diagram shows a vector, which has both size and direction. The magnitude is the length of the arrow, representing the 'how much' of a quantity.

Front

Linear Motion Noun

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[lin-ee-er moh-shun]

Back

Linear Motion

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Movement that occurs along a straight line path, without any change in direction.

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Example: A train moving along a straight track demonstrates linear motion. Its change in position, called displacement, can be positive or negative depending on direction.

Front

Distance Noun

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[dis-tuhns]

Back

Distance

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A scalar quantity representing the total length of the path traveled by an object between two points.

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Example: This diagram shows that distance is the total length of the path traveled (the winding 8 km road), not the straight-line path between start and end.

Front

Displacement Noun

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[dis-pleys-muhnt]

Back

Displacement

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A vector quantity representing the shortest distance and direction from an object's starting point to its ending point.

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Example: This diagram shows a round trip from home to school and back. Although a distance was traveled, the total displacement is zero because the start and end points are the same.