Critical velocity

Critical velocity may refer to


 * Critical ionization velocity, relative velocity between a neutral gas and plasma at which the neutral gas will start to ionize
 * Speed of sound, at the throat of a rocket (otherwise known as throat velocity)
 * Landau critical velocity, constant velocity of a superfluid equivalent to the bandgap width divided by the fermi momentum
 * Velocity at which a liquid transitions from subcritical flow to supercritical flow
 * The break-up velocity of a rapidly spinning star


 * Velocity at which leukocytes switch from rolling to freely flowing in a blood vessel