Reflection of waves
Vibrations that transfer energy from place to place without the transference of matter. - including sound and light waves - can be reflected at the boundary between two different materials. The reflection of sound causes echoes.
The law of reflection states that:
angle of incidence = angle of reflection
For example, if a light ray hits a surface at 32°, it will be reflected at 32°.
The Angle between the normal and the incident ray. and The angle between the reflected ray and the normal (the imaginary line drawn at 90 degrees to the reflecting surface). are measured between the light ray and the An imaginary but useful line at right angles to the boundary between air/glass. All angles are measured to this line. - an imaginary line at 90° to the surface. The diagram shows a water wave being reflected at a barrier.