Blackboard Optics Refraction at Flat Surfaces
Purpose
Students observe how light rays bend when entering and exiting transparent plexiglass blocks, verifying Snell's Law quantitatively by tracing rays on paper. The setup also demonstrates total internal reflection and dispersion with a prism.
Figure 1:
A single ray refracts as it enters and exits a rectangular plexiglass block. The emerging ray is parallel to the incident ray but laterally displaced.
Figure 2:
A ray enters the rectangular block at a steep angle and undergoes total internal reflection at the far surface, demonstrating the critical angle.
Figure 3:
A prism disperses white light into its component colors, showing that the refractive index depends on wavelength.