Definition

1. Noun (Physics): The principle that the total linear momentum of a closed or isolated system remains constant if no external net force acts on it. This means the combined momentum of all objects within the system before an interaction (like a collision or explosion) is equal to the combined momentum after the interaction.

Usage and Examples

• Noun:
  • The rocket's propulsion is a classic demonstration of the conservation of momentum; the exhaust gases shoot backward, and the rocket moves forward.
  • In a perfectly elastic collision between two billiard balls, both kinetic energy and conservation of momentum are observed.
  • Engineers must account for conservation of momentum when designing safety features for vehicles.

Advanced Usage

• "Conservation of angular momentum": A related principle stating that the total angular momentum of a system remains constant unless acted upon by an external torque. This explains phenomena like a spinning ice skater pulling their arms in to spin faster.
  • The stability of a gyroscope is due to the conservation of angular momentum.

Variants and Related Words

• Momentum (n): The quantity of motion of a moving body, measured as the product of its mass and velocity.
  • The truck, due to its large mass, had tremendous momentum.
• Closed system / Isolated system (n): A physical system that does not exchange matter with its surroundings and is not subject to external net forces (for momentum conservation).
  • For momentum to be perfectly conserved, we often model the event within an isolated system.

Synonyms

• Momentum conservation: A direct synonym.
• Principle of momentum conservation: A more formal equivalent.

Related Phrases and Concepts

• Law of conservation of energy: A fundamental law stating that the total energy in an isolated system remains constant.
• Newton's third law of motion: Often linked conceptually, as the equal and opposite forces described by Newton's third law are the mechanism that ensures momentum is conserved within a system.
  • When you push against a wall, the wall pushes back with equal force, illustrating Newton's third law and resulting in no net change in the system's momentum.

Noun

1. the principle that the total linear momentum in a closed system is constant and is not affected by processes occurring inside the system