What is displacement in waves?
How far a point on the wave is from the rest position
What does a vibrating object like a speaker vibrate?
Air particles.
What unit do we use to measure the frequency of a sound wave?
Hertz (Hz)
What does frequency mean?
How often / How many ... per second.
What is an echo? .... echo?
A reflection of a sound wave from a surface.
How do we calculate speed?
Distance ÷ Time
Why do we see ourselves in mirrors?
Because mirrors reflect light.
How fast does light travel?
300 000 000 metres per second
True or False. The higher the refractive index, the faster the light travels though a material.
False. The higher the refractive index, the slower it travels.
Does the human eye have a convex lens or a concave lens?
A convex lens.
What do we call the splitting of white light into different individual colours?
Dispersion.
