The uncertainty in this quantity times the uncertainty in position must be at least h-bar over two, according to the Heisenberg uncertainty principle.
The canonical variety of this quantity is equal to the partial derivative of the Lagrangian with respect to q-dot. Wave vectors exist in a space named for this quantity, which for a wave is equal to h-bar times the wave number. At relativistic speeds, energy equals this quantity times the speed of light, while classically, kinetic energy equals this quantity squared divided by two times mass. The uncertainty in this quantity times the uncertainty in position must be at least h-bar over two, according to the Heisenberg uncertainty principle. Unlike kinetic energy, this quantity is always conserved, even in inelastic collisions. For 10 points, name this quantity equal to mass times velocity.
The canonical variety of this quantity is equal to the partial derivative of the Lagrangian with respect to q-dot.
linear momentum [do not accept "angular momentum" at any point]