Finally, the important features of the laws and their relation with other laws are brought out and reinforced in the students' mind by applying them to a variety of physical situations. Because of their conceptual importance, both as a starting point in physical reasoning and as a tool for codifying diverse physical phenomena, the various conservation laws receive particularly heavy emphasis. Wherever appropriate, all physical quantities are first introduced by use of operational definitions. In the students' subsequent capacity as a professional they may well be called upon to apply physical laws in regions bordering on their limits of validity. Therefore, they should be able to reexamine critically and systematically all basic definitions and derived results.
Lecture demonstrations are an important component of the course.
They should convince students that a physical principle is valid and to leave them with a memorable impression of how the principle operates. In the laboratory, the validity of idealized assumptions is questioned. Some laboratories use conventional formats which verify a law, but others give the students a view of a much more genuine experimental situation. Exposure to electronic instrumentation, particularly the oscilloscope, is desirable. Excessive zeal regarding precise measurement is generally avoided at this level.