Inertia

Front

Inertia Noun

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[in-ur-shuh]

Back

Inertia

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The tendency of an object to resist any change in its state of motion, whether at rest or moving.

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Example: A ball at rest stays at rest until kicked. A ball in motion stays in motion until stopped by a net. This is inertia.

Front

Mass Noun

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[mas]

Back

Mass

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The measure of an object's inertia, which indicates the amount of matter the object contains.

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Example: This image shows inertia, the resistance to a change in motion. When the car stops suddenly, the box's mass causes it to continue moving forward.

Front

Force Noun

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[fors]

Back

Force

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A push or pull upon an object that can cause it to change its velocity, meaning to accelerate.

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Example: A person applies a force (a push) to an object to overcome its inertia and change its state of motion from rest.

Front

External Force Noun

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[ek-stur-nl fors]

Back

External Force

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A force that originates from outside an object and acts upon it to change its state of motion.

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Example: An external force, like the Magnus force on a spinning soccer ball, causes the ball to change its straight path of motion (inertia).

Front

Unbalanced Force Noun

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[un-bal-uhnst fors]

Back

Unbalanced Force

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A net force that is not zero, causing a change in an object's motion, such as its speed or direction.

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Example: When the hand releases the ball, gravity becomes an unbalanced force, causing the ball to change its motion and accelerate downwards.

Front

Velocity Noun

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[vuh-los-i-tee]

Back

Velocity

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A measure of the rate and direction of an object's change in position over a period of time.

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Example: Velocity is an object's speed in a specific direction. The straight path shows a constant velocity, while the winding path shows a changing velocity because the direction is always changing.

Front

Constant Velocity Noun

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[kon-stuhnt vuh-los-i-tee]

Back

Constant Velocity

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A state in which an object moves at a steady speed and in a single, unchanging direction.

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Example: This velocity-time graph shows a horizontal line, indicating that the object's velocity (v) does not change as time (t) passes, remaining constant at 5 m/s.

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 be a change in speed or direction.

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Example: This diagram shows Newton's Second Law, F=ma, where acceleration ('a') is the result of applying a net force ('F') to an object's mass ('m').

Front

Friction Noun

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[frik-shuhn]

Back

Friction

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A force that opposes the motion of objects, acting between surfaces that are in contact with each other.

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Example: A car rolls from a smooth to a rough surface, where the force of friction acts in the opposite direction of its motion, slowing it down.