PASCO OS-8500 INTRODUCTORY OPTICS SYSTEM - Manual (Page 16)

Introductory Optics System 012-02744K
®
10
Procedure
Set up the equipment as shown in Figure 2.1. Adjust the components so a single ray of light
is aligned with the bold arrow labeled “Normal” on the Ray Table Degree Scale. Carefully
align the flat reflecting surface of the mirror with the bold line labeled “Component” on the
Ray Table. With the mirror properly aligned, the bold arrow on the Ray Table is normal (at
right angles) to the plane of the reflecting surface.
Rotate the Ray Table and observe the light ray. The angles of incidence and reflection are
measured with respect to the normal to the reflecting surface, as shown in Figure 2.2.
By rotating the Ray Table, set the angle of incidence to each of the settings shown in Table
2.1. For each angle of incidence, record the angle of reflection (Reflection
1
). Repeat your
measurements with the incident ray coming from the opposite side of the normal (Reflec-
tion
2
).
➀ Are the results for the two trials the same? If not, to what do you attribute the differences?
________________________________________________________________________
➁ Part of the law of reflection states that the incident ray, the normal and the reflected ray all lie
in the same plane. Discuss how this is shown in your experiment
_____________________________________________________________________________________________.
➂ What relationship holds between the angle of incidence and the angle of reflection?
______________________________________________________________________________
Additional Questions
➀ The Law of Reflection has two parts. State both
parts.
➁ You were asked to measure the angle of reflection
when the ray was incident on either side of the
normal to the surface of the mirror. What advan-
tages does this provide?
➂ Physicists expend a great deal of energy in attempts
to increase the accuracy with which an exact law
can be proven valid. How might you test the Law
of Reflection to a higher level of accuracy than in
the experiment you just performed?
Angle of: Incidence Reflection
1
Reflection
2
0°
10°
20°
30°
40°
50°
60°
70°
80°
90°
Table 2.1 Data