This chapter deals with the description of periodic phenomena in nature that can be represented as oscillations or waves.
To begin with, the relationships discussed in the previous chapter are applied to mechanical oscillations and illustrated using different types of pendulums. In addition to these idealized systems, this section also covers damped and forced oscillations.
In the next step, propagating oscillations in the form of waves are examined, and a mathematical framework for their description is developed.
Finally, the focus shifts to acoustic waves, which are particularly important in medical applications. Key concepts such as sound pressure and loudness are addressed in detail.
Ultrasound is given special attention, including its use in combination with sonar and Doppler ultrasound.