Wikipedia
Critical velocity is the speed that a falling object reaches when gravity and air resistance equalize on the object.
Critical velocity may refer to
- Critical ionization velocity
- speed of sound at the throat of a rocket (otherwise known as throat velocity)
- constant velocity of a superfluid in capillaries which is equivalent to the bandgap width divided by the fermi momentum (otherwise known as critical speed or the Landau critical velocity).
- velocity at which a liquid transitions from subcritical flow to supercritical flow. In normal hydraulics, this velocity can be derived when the Froude number is unity.
- in hydrofracking, the velocity of the fluid flow above which liquid droplets do not accumulate in the well.
- velocity that can be maintained when running at maximal oxygen consumption ( VO2 max)
- velocity at which leukocytes switch from rolling to freely flowing in a blood vessel
Usage examples of "critical velocity".
Now that we've discovered why starships disappear at fifty light-years or so, it can be done by stages, or by coasting after the critical velocity is reached.
Like most contemporary starships, she employed antigravity generators for Hypolight-speed travel, switching to her four matched Sheldon Drive crystals (for both propulsion and negation of relativistic mass/time effects) only when it was desired to surpass the critical velocity of LightSpeed.
I listened to the terrific thundering of the thruster engines, which continued to crescendo even after we had reached critical velocity.
We'll hit atmosphere in about half an hour, somewhat under critical velocity.