Principle
The aim of this experiment is to experimentally determine the
laws of reflection.
In doing so, we deliberately refrain from introducing the terms
"angle of incidence", "normal to the reflecting surface" and "angle
of reflection" to begin with. In the course of the experiment the
students become acquainted with these terms which
are appropriate for the unequivocal determination of the
investigated quantities. However, the students should be told
before beginning the experiment that it is helpful to
measure angles and to compare them to investigate the correlation
between the direction of the incident and the reflected light
beam.
The experiment consists of two parts.
In the first part the angular dependency of reflection is
investigated on a plane mirror, and the law of reflection with its
statements concerning angle of incidence and angle of reflection is
determined.
In the second part of the experiment the students indirectly prove
that the incident and reflected beams of light and the normal to
the reflecting surface all lie in the same plane. By changing the
position of one half of a sheet of paper, it is shown that
only when both halves of the sheet are in the same plane is
the reflected light beam visible in its entire length.
Thus, the two partial experiments form a unit in terms of the
comprehensive experimental determination of the law of reflection;
however, they can also be conducted separately.
Similarly, a differentiated application in a group of students or a
complete omission of the experimental determination of the
positional relationships is possible.
Benefits
- Multifunctional light box - All-in-one: Can be used for geometric optics on the table, colour mixing and on an optical bench
- Extension with others sets at anytime, no additional light sources needed, recognition value for students
Tasks
How can you look around the corner of a house with a mirror? In this experiment, the connection between the mirror's incident and reflected light beam is investigated. In a second step it is determined how to hold a piece of paper to see the reflected light beam in its entire length.



