In an irrotational fluid, it can be expressed as the gradient of a fluid potential, since in that case the curl of this quantity, also called the vorticity, is zero.
A relativistic form of this quantity can be expressed as the four-vector tangent of a world line. The divergence of this quantity is zero for an incompressible fluid. In an irrotational fluid, it can be expressed as the gradient of a fluid potential, since in that case the curl of this quantity, also called the vorticity, is zero. For a planet in orbit around the sun, the areal form of this quantity is constant. The force on a charged particle due to a magnetic field equals the charge of the particle times the (*) cross product of this quantity and the magnetic field, according to the Lorentz force law. The kinetic energy equals one half times m times the magnitude of this quantity squared. For 10 points, name this vector quantity, the time derivative of position, which can be given as a speed and a direction.
A relativistic form of this quantity can be expressed as the four-vector tangent of a world line.
velocity [accept fluid velocity, velocity field, etc]