Reflection of light
Rotate the mirror and trace where the light comes from and where it goes.
The angle of reflection equals the angle of incidence, both measured from the mirror's normal. When you change the mirror's orientation, this experiment keeps the chosen angle of incidence fixed, so the light source and the reflected path rotate together with the mirror.
Reflection and incidence angles
Think about it
If the incident ray makes an angle of 30° with the mirror, what is the angle of reflection?
The angle of reflection is 60°. The angle of incidence is measured from the normal, so it is 90° − 30° = 60°; by the law of reflection, the angle of reflection is also 60°.
Model assumptionsPlane mirror · ideal specular reflection · angles measured from the normal · dots only indicate direction of travel
Data log
Set the parameters and click “Record data”. Record several rows with different parameters to plot their relationship and fit a straight line; pause and record at different times to study how a reading changes with time.