The speed of light in a vacuum is
300 000 km per second
30 000 km per second
3 million km per second
30 km per second

The ratio of the speed of light in a vacuum to the speed of light in a material is known as Refractive Index
Dispersive Index
Relational Index
Reflective Index

When identical waves overlap they may reinforce or cancel each other out this is known as Diffraction
Interference
Dispersion
Diffusion

When light passes through a prism and split into different spectral colours it has undergone Diffraction
Interference
Dispersion
Diffusion

The speed of sound in concrete is around 330 metres per second
1400 metres per second
30 metres per second
5000 metres per second

The speed of light in glass is 200 000 km per second
20 000 km per second
2 million km per second
20 km per second

Which of these materials has the highest refractive index of 2.42 ? Perspex
Water
Diamond
Glass

The speed of sound in water is around 330 metres per second
1400 metres per second
30 metres per second
5000 metres per second

Sound waves above 20 000HZ or just out of the range of human hearing are known as Ultrasonic Waves
Light Waves
XRays
Ultrafast Waves

The speed of sound in air is around 330 metres per second
1400 metres per second
30 metres per second
5000 metres per second

