Additional resources:
Review and reflection
9.1a Describing Simple Harmonic Motion
9.1b Energy and Simple Harmonic Motion
9.1c The simple pendulum and mass-spring systems
Diffraction at a single slit
9.3a Young's double-slit experiment
9.3b Multiple slits and diffraction gratings
9.3c Thin film interference
How close together can you see.
9.5a Doppler Effect in sound
9.5b Doppler effect in EM radiation