WavesLesson 1.1:  Understanding waves

Lesson 1.2:  Reflection of waves

Lesson 1.3:  Refraction of Waves

Lesson 1.4:  Diffraction Waves

Lesson 1.5:  Interference of Waves

Lesson 1.6:  Sound Waves

Lesson 1.7:  Electromagnetic Waves

Reflection – the change of direction of waves, when they hit a reflective surface.

• In reflection, the direction of propagation of waves changes and the angle of reflection is always equal to the angle of incidence.

• λ of reflected waves = λ of incidence waves• f of reflected waves = f of incidence waves• v of reflected waves = v of incidence waves

Refraction – the change of direction of travel when the waves cross from a medium to a new medium.

Diffraction – spreading of waves that happen when waves move through a small opening or round a small obstacle.

Interference – the superposition of two waves when they meet each other.Interference is the effect of superposition of two waves from two coherent sources.

• Two sources are said to be coherent if

- they produce waves of the same frequency

- they produce waves of the same phase (or with constant phase difference)

Constructive Interference

Destructive Interference

Interference pattern produce by water waves