Waves, Light & Sound

What this lesson covers

Waves, Light & Sound is a 8-part O Level Physics lesson. Each part makes one point and then hands over to the next, so it can be read in a sitting or picked up again at the part you stopped on. It defines the idea in plain words before using it, works through an example step by step, breaks the topic into its parts and compares them, shows where it is used outside the textbook, names the mistakes that cost marks in an exam, ends with a recap of what to remember.

How it begins

A wave transfers energy without transferring matter. Transverse: vibrations perpendicular to the direction of travel, light, all EM waves, water surface waves. Longitudinal: vibrations parallel to travel, as compressions and rarefactions, sound. Wavelength λ: distance between two successive crests, in metres. Frequency f: waves per second, in hertz. Period T = 1/f.

The 8 parts

1. The vocabulary you will be asked to define
2. Reflection, refraction, and the refractive index
3. Total internal reflection and the critical angle
4. Lenses and the ray diagram that must be drawn correctly
5. The EM spectrum, and sound
6. Where marks go
7. What to remember
8. Watch one worked through