20 km per second 200 000 km per second 2 million km per second 20 000 km per second
Diffusion Diffraction Dispersion Interference
5000 metres per second 330 metres per second 30 metres per second 1400 metres per second
Ultrafast Waves Ultrasonic Waves X-Rays Light Waves
Glass Perspex Diamond Water
Reflective Index Refractive Index Relational Index Dispersive Index
30 km per second 300 000 km per second 3 million km per second 30 000 km per second