Equilibrium

Front

Angular Displacement Noun

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[ang-gyuh-ler dis-pleys-muhnt]

Back

Angular Displacement

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The change in the angle of an object as it rotates around an axis, typically measured in radians or degrees.

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Example: As an object rotates, angular displacement is the angle (θ) through which a point on the object moves around a central axis or point.

Front

Radian Noun

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[rey-dee-uhn]

Back

Radian

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A unit of angle where the arc length of a circle's sector is equal to the length of its radius.

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Example: This diagram shows that one radian is the angle at the center of a circle where the arc length along the edge is equal to the circle's radius (r).

Front

Angular Velocity Noun

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[ang-gyuh-ler vuh-los-i-tee]

Back

Angular Velocity

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The rate at which an object rotates about an axis, specifying the change in angular displacement over time.

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Example: This image shows a Ferris wheel rotating. Angular velocity is how fast it spins, measured by the angle it turns (like 30° or 60°) over a period of time.

Front

Angular Acceleration Noun

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[ang-gyuh-ler ak-sel-uh-rey-shuhn]

Back

Angular Acceleration

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The rate of change of angular velocity, indicating how quickly an object's rotational speed is changing over time.

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Example: Applying a tangential force to a bike tire causes it to spin faster, demonstrating how a force creates a change in rotational speed, known as angular acceleration.

Front

Torque Noun

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[tawrk]

Back

Torque

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A twisting force that tends to cause rotation, measured as the product of force and perpendicular distance from the axis.

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Example: This image shows how a force (a child's weight) applied at a distance from a pivot (fulcrum) creates a turning effect called torque.

Front

Lever Arm Noun

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[lev-er ahrm]

Back

Lever Arm

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The perpendicular distance from the axis of rotation to the line along which a force is applied.

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Example: This diagram shows a balanced lever. The lever arm is the distance from the fulcrum to a force. A longer lever arm allows a smaller force to balance a larger force, achieving equilibrium.

Front

Moment of Inertia Noun

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[moh-muhnt uhv in-ur-shuh]

Back

Moment of Inertia

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A measure of an object's resistance to changes in its rotational motion, dependent on its mass and mass distribution.

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Example: This image shows that moment of inertia depends on mass distribution; a skater with arms in has less inertia than one with arms out.

Front

Center of Mass Noun

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[sen-ter uhv mas]

Back

Center of Mass

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The unique point in an object or system which moves as if all the system's mass were concentrated there.

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Example: The center of mass (C) is the balance point of a system. For two connected objects, it is closer to the object with more mass (m1).

Front

Stability Noun

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[stuh-bil-i-tee]

Back

Stability

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The ability of an object to maintain its equilibrium or resist being tipped over when subjected to external forces.

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Example: This image shows two people pulling a rope with equal and opposite force. Because the forces are balanced, there is no movement, demonstrating equilibrium and stability.

Front

Base of Support Noun

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[beys uhv suh-pawrt]

Back

Base of Support

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The area enclosed by the points of contact an object has with the surface that is supporting it.

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Example: The image shows that the base of support is the area enclosed by the parts of the body in contact with a surface, such as a person's feet.