Wave Reflection (continued)

Two-dimensional wave reflection

When a wavefront propagating on a liquid surface hits an obstacle, each point on the front is reflected, so it is possible to represent them by their wave rays.

The reflection of wave rays is governed by two laws of reflection, which are presented as:

  • 1st Law of Reflection: The incident radius, the reflected radius and the line perpendicular to the reflecting surface at the point of incidence are always contained in the same plane;
  • 2nd Law of Reflection: The angles formed between the incident radius and the perpendicular line and between the reflected radius and the perpendicular line always have the same measurement.

Like this:

As stated by Law 2, angles have equal value, therefore:

Then one can imagine that the reflection of the waves happens as if it were reflected in a mirror perpendicular to the point of incidence.

Consider the reflection of circular waves: