In aerodynamic theory, the value of this quantity at a point can be found by dividing the strength of the vortex by two times pi times the distance from the vortex line by an application of the Biot-Savart Law. For a vector field of this quantity, if the divergence is zero, 
In aerodynamic theory, the value of this quantity at a point can be found by dividing the strength of the vortex by two times pi times the distance from the vortex line by an application of the Biot-Savart Law. For a vector field of this quantity, if the divergence is zero, a fluid is incompressible. The Maxwell-Boltzmann distribution describes this property of particles in gasses, and vorticity is the curl of this quantity. One effect states that an increase in this quantity occurs with a decrease in pressure or potential energy, and that effect is named for Bernoulli. For 10 points, name this vector quantity that is the measurement of the rate of change in position.
In aerodynamic theory, the value of this quantity at a point can be found by dividing the strength of the vortex by two times pi times the distance from the vortex line by an application of the Biot-Savart Law.
velocity [accept speed or rate of flow until "vector quantity"]