velocity

/vi'lɔsiti/

Thân thiện

The car's velocity is constant as it travels down the straight highway.

Definition

1. Noun:
   • Speed of motion in a specific direction: The rate at which an object changes its position. It is a vector quantity, meaning it has both magnitude (speed) and direction.
   • Rate of occurrence or action: (In a more general, often figurative sense) The speed at which something happens or changes.

Usage and Examples

• Noun (Physical Science):
  • The car's velocity was 60 miles per hour due north. (This specifies both how fast and in which direction it was moving.)
  • To calculate the escape velocity, you need to know the planet's mass and radius.
• Noun (General/FIgurative):
  • The velocity of technological change is astonishing. (This describes the rapid rate of change.)
  • Money changes hands with great velocity in a bustling market.

Advanced Usage

• Terminal velocity: The constant maximum speed reached by a falling object when the force of gravity is balanced by the drag force of the medium (e.g., air).
  • A skydiver in a spread-eagle position reaches a terminal velocity of about 120 mph.
• Angular velocity: The rate of change of angular position of a rotating object.
  • The angular velocity of the wheel is measured in radians per second.
• Relative velocity: The velocity of an object as observed from a particular frame of reference.
  • The relative velocity of two trains approaching each other is the sum of their individual speeds.

Variants and Related Words

• Velocimeter (n): An instrument for measuring velocity.
• Velocious (adj): (Rare) Characterized by speed; swift.

Synonyms

• Speed: (The key difference is that "speed" is a scalar quantity—it only has magnitude, not direction.)
• Rate: A measure of how quickly something happens.
• Swiftness: Rapidness of movement.
• Pace: The speed at which something progresses.

Related Phrases and Compounds

• Muzzle velocity: The speed of a projectile as it leaves the muzzle of a firearm.
• Initial velocity: The velocity of an object at the start of a time period or motion.
• Velocity vector: A vector that represents an object's velocity, showing both magnitude and direction.

Notes on Usage

• In precise scientific and engineering contexts, "velocity" is distinguished from "speed" by its inclusion of directional information. In everyday language, they are often used interchangeably, though "velocity" can sound more technical.
• It is commonly used in physics, mechanics, astronomy, and engineering.

Học thuật

Noun

1. distance travelled per unit time

Từ đồng nghĩa

• speed