Presents an alternative approach for deriving the perturbation formulas for the energy in quantum mechanics. The procedure focuses on the solution of the secular equation D(E)=O, and then derives the first-, second-, and third-order formulas by the same method. (GA)

States and proves some useful identities in normal ordering. The identities can be very useful in ordinary quantum-mechanicaland many-body problems. (Author/GA)

Formulas are derived for the energy, momentum, and angular momentum transmitted by waves of arbitrary shape in an inextensible string by pure transverse waves in a string using Tait's procedure. (Author/CP)

Demonstrates that when a system of attracting or repelling bodies is bound, its rest mass will generally be different than the sum of the rest masses of the individual bodies. The mass excess or defect is simply related to the stored potential energy of the system. (Author/MLH)

Shows that the basic properties of spherical harmonics follow in a simple and elegant way from the commutation relations for angular momentum operators and the commutation relations between these operators and arbitrary vector operators. (Author/HM)

Provides a detailed discussion of a Lagrange formalism in classical momentum space. (SL)

Rewriting the usual relativistic equations in equivalent forms can help students recognize the relation between classical and relativistic mechanics. The derivation of relativistic equations is facilitated by means of simple algebraic generalizations of proofs often used in teaching their classical analogs to students who have not studied…

Distinguishes between the work done by the source and the work received by the system. Shows that a comparison of the magnitudes of quasistatic and nonstatic work can be carried out only through the use of the laws of thermodynamics. (GA)

Expressions to describe fringe contours in the region of interference of two coherent beams are derived for three combinations of plane and spherical wave geometrics. (Author/SL)

Provides an analytical solution of a model representing the collision of an atom with a harmonic oscillator, interacting via a repulsive square well potential. Presents results for various energies and strengths of inelastic scattering. (Author/CP)

Reports on the production, properties, and internal structure of several of the elementary particles in language understandable to the high school student. (CP)

Describes the relationship existing between coefficient of performance (COP) and energy efficiency ratio (EER) in air conditioning units and introduces new efficiency parameters measured relative to the energy extracted from the primary energy source. (SL)

Provides a definition of electric energy density by drawing a circuit analog. (SL)

Presents a method for describing the electromagnetic field within a wave guide which permits the application of the formalism of quantum mechanics. (SL)

The exact dynamics is presented for a two-particle model. By expressing canonical ensemble averages in terms of time-energy averages, a deeper understanding of the dissociation property is achieved. (BB)