Wave Behaviour

What is reflection?

When a wave bounces off a boundary and changes direction

What is the law of reflection?

Angle of incidence equals angle of reflection

What is the angle of incidence?

The angle between the incoming wave (or ray) and the normal line

What is the angle of reflection?

The angle between the reflected wave (or ray) and the normal line

What is a normal line?

An imaginary line drawn at 90° to the surface at the point of incidence

What is refraction?

The change in direction of a wave due to a change in speed when entering a different medium

Why does refraction happen?

Because wave speed changes when entering a different medium

What happens to wave speed in a denser medium?

It decreases

What happens to wavelength in a denser medium?

It decreases

What happens to frequency in refraction?

It stays the same

What happens to direction in refraction?

The wave bends towards or away from the normal depending on speed change

What is diffraction?

The spreading out of waves when they pass through a gap or around an obstacle

When is diffraction greatest?

When the gap size is similar to the wavelength

What happens if the gap is much larger than the wavelength?

There is little diffraction

What happens if the gap is smaller than the wavelength?

The wave spreads out significantly

Why does diffraction occur?

Because different parts of the wavefront spread out after passing an edge or gap

Give an example of diffraction in real life?

Sound being heard around corners

Does reflection change wave speed?

No, wave speed stays the same in the same medium

Does refraction change frequency?

No, frequency remains constant

What changes during refraction?

Speed and wavelength change

What is the key idea linking all wave behaviour?

Energy is transferred, not matter, and waves respond to boundaries by reflection, refraction, or diffraction