terminal velocity
Học thuậtThân thiện
Definition
- 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
- the constant maximum velocity reached by a body falling through the atmosphere under the attraction of gravity