Answer to Question #116647 in Physics for Sarah

Question

Describe how the student adjusts the apparatus to measure the critical angle.You may use diagram to help your explanation.

Answer 1

The laser (red) fixed on a limb emits light, the student adjusts the angle until the light beam reflects from the surface of the material students study. The material is fixed so that one of its surfaces lied on a diameter of the limb. The minimal angle when the reflection occurs is the critical angle. The angle will be greater or equal to critical if the students do not see the light spot above the horizontal surface.