ABSTRACT
In the previous chapter, we encountered a number of energy conserving physical systems that ex-
hibit simple harmonic oscillation about a stable equilibrium state. One of the main features of such
oscillation is that, once excited, it never dies away. However, the majority of the oscillatory sys-
tems that we encounter in everyday life suffer some sort of irreversible energy loss while they are
in motion, due, for instance, to frictional or viscous heat generation. We would therefore expect
oscillations excited in such systems eventually to be damped away. The aim of this chapter is to
examine so-called damped harmonic oscillation, and also to introduce the differential equation that
governs such motion, which is known as the damped harmonic oscillator equation. In addition, we
shall examine the phenomenon of resonance in periodically driven, damped, oscillating systems. In
this chapter, examples are again drawn from simple mechanical and electrical systems.
