This operator’s commutator with an operator A times i over h-bar equals the time derivative of A’s expectation value minus the expectation value of A’s time derivative (10[1])in the Heisenberg picture. This quantity’s Poisson bracket with a constant of motion equals zero. If this quantity is time-independent, then the time evolution operator equals this quantity’s exponential. This quantity’s operator on the wavefunction is i h-bar times the wavefunction’s time derivative in the time-dependent Schrodinger equation, (10[1])while its time-independent form sets this quantity’s operator on psi equal to “E psi.” The Legendre transform of the Lagrangian equals this quantity, which is minimized at the ground state. (10[1])For 10 points, what quantity is the sum of the “potential” and “kinetic” forms of a quantity measured in joules? ■END■