angular momentum

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angular momentum

A figure skater increases her angular momentum during a spin.

Definition
  1. Noun:
    • A physics quantity: Angular momentum is the rotational equivalent of linear momentum. It is a measure of the amount of rotation an object has, taking into account its mass, shape, and speed of rotation.
    • A conserved property: In a closed system with no external torque, the total angular momentum remains constant. This principle is fundamental in physics.
Usage Examples
  • Noun:
    • The angular momentum of the spinning ice skater increases when she pulls her arms in.
    • Conservation of angular momentum explains why a planet's orbit is stable.
    • Calculating the angular momentum requires knowing the object's moment of inertia and angular velocity.
Advanced Usage

  • "Conservation of angular momentum": A fundamental law of physics stating that if no external torque acts on a system, its total angular momentum remains unchanged.

    • The conservation of angular momentum is why a spinning top stays upright.

  • "Spin angular momentum": Angular momentum associated with an object's intrinsic rotation about its own axis, distinct from orbital angular momentum.

    • Electrons possess an intrinsic form of angular momentum called spin.

  • "Orbital angular momentum": Angular momentum associated with the motion of an object along an orbit or path around a point.

    • The Earth has orbital angular momentum from its revolution around the Sun.
Variants and Related Words
  • Momentum (n): The quantity of motion of a moving body, measured as a product of its mass and velocity. (Linear momentum is the counterpart to angular momentum).
  • Torque (n): A force that causes rotation or a change in angular momentum.
  • Moment of inertia (n): A measure of an object's resistance to changes in its rotation rate, crucial for calculating angular momentum.
Synonyms
  • Rotational momentum: A direct synonym emphasizing the rotational nature of the quantity.
  • Moment of momentum: An older, less common term with the same meaning.
Related Phrases
  • "Angular momentum vector": Angular momentum is a vector quantity, meaning it has both magnitude and direction.
    • The direction of the angular momentum vector is perpendicular to the plane of rotation.
Related Concepts
  • "Angular velocity": The rate at which an object rotates or revolves, expressed in radians per second.
  • "Gyroscopic stability": The stabilizing effect resulting from the conservation of angular momentum, as seen in gyroscopes and bicycles.
angular momentum

A figure skater increases her angular momentum during a spin.

Noun
  1. the product of the momentum of a rotating body and its distance from the axis of rotation
    • any rotating body has an angular momentum about its center of mass
    • angular momentum makes the world go round