Force and Motion

Front

Motion Noun

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[moh-shun]

Back

Motion

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

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Example: The image shows how action and reaction forces affect a car's motion, demonstrating Newton's third law.

Front

Reference Frame Noun

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[ref-er-uhns freym]

Back

Reference Frame

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

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Example: The image shows how a person on a platform sees a person on a moving train as moving, while the person on the train sees the platform person as moving.

Front

Relative Motion Noun

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[rel-uh-tiv moh-shun]

Back

Relative Motion

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Motion that is described based on a reference frame that may itself be in motion.

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Example: A person walking inside a moving train shows relative motion by comparing speeds to a ground observer.

Front

Speed Noun

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[speed]

Back

Speed

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The rate at which an object covers a certain distance in a given amount of time.

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Example: A car travels a certain distance in a specific time, showing speed as distance divided by time.

Front

Instantaneous Speed Noun

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[in-stuhn-tey-nee-uhs speed]

Back

Instantaneous Speed

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The exact speed of an object measured at a specific moment or instant in time.

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Example: A speedometer shows the speed of a vehicle at a specific moment, demonstrating instantaneous speed.

Front

Velocity Noun

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[vuh-los-i-tee]

Back

Velocity

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The speed of an object in a specific, given direction, making it a vector quantity.

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Example: Two cars moving at the same speed but in opposite directions show how velocity includes direction.

Front

Acceleration Noun

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[ak-sel-uh-rey-shun]

Back

Acceleration

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The rate at which an object's velocity changes, involving a change in speed, direction, or both.

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Example: The image shows acceleration by comparing jogging and sprinting speeds, highlighting changes in velocity.

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 child pushing a door demonstrates force as a push that can change an object's 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 only when it is in direct physical contact with another.

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Example: Two people pushing a box from opposite sides demonstrate contact force.

Front

Friction Noun

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[frik-shun]

Back

Friction

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A contact force that opposes motion when two surfaces rub against each other.

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Example: A box is pushed on a surface, and friction acts in the opposite direction to resist the motion.