Definition

1. Noun:
   • The constant maximum speed attained by a freely falling object through a fluid, such as air: It is the speed at which the downward force of gravity is balanced by the upward forces of drag and buoyancy, resulting in no further acceleration.

Usage

• Terminal velocity is a concept in physics, specifically fluid dynamics and mechanics.
• It is used when discussing the motion of objects falling through a resisting medium like air or water.
• The value of terminal velocity depends on the object's mass, cross-sectional area, drag coefficient, and the density of the fluid.

Examples

• Noun:
  • A skydiver in a stable, belly-to-earth position reaches a terminal velocity of about 200 km/h before deploying the parachute.
  • The hailstone stopped accelerating when it achieved its terminal velocity in the storm cloud.
  • Calculating the terminal velocity of a raindrop is important for understanding precipitation physics.

Advanced Usage

• "to reach terminal velocity": to achieve this constant maximum speed.
  • The meteorite fragment began to glow as it reached terminal velocity in the lower atmosphere.
• The concept is often applied metaphorically to describe a point where no further progress or increase is possible.
  • The company's growth has hit its terminal velocity in the current market.

Variants and Related Words

• Terminal speed: A synonymous term, sometimes used interchangeably, though "velocity" is a vector quantity (having direction) and "speed" is scalar.
• Free fall: The motion of an object where gravity is the only force acting upon it, prior to reaching terminal velocity in a medium.
• Drag force: The resistance force that opposes the motion and balances weight at terminal velocity.
• Stokes' law: A formula used to calculate the terminal velocity of small spherical objects in a viscous fluid.

Synonyms

• Constant velocity: (in the specific context of a falling object) the final, unchanging speed.
• Limiting speed: the maximum attainable speed under the given conditions.
• Final velocity: (in this specific physical context) the velocity achieved when acceleration ceases.

Related Phrases

• To fall at terminal velocity: to descend at this constant maximum speed.
  • The payload was designed to survive impacting the ground while falling at terminal velocity.
• Terminal velocity regime: the state or condition of moving at terminal velocity.
  • Once in the terminal velocity regime, the object's kinetic energy remains constant.

Notes

• Terminal velocity is not a universal constant; it is specific to each object-fluid combination.
• In a vacuum, where there is no fluid resistance, there is no terminal velocity; objects continue to accelerate due to gravity.

Noun

1. the constant maximum velocity reached by a body falling through the atmosphere under the attraction of gravity