Mission RL2 Light Speed and Refraction
Hold down the T key for 3 seconds to activate the audio accessibility mode, at which point you can click the K key to pause and resume audio. Useful for the Check Your Understanding and See Answers.
The diagram at the right depicts a ray of light moving from a medium in which it moves relatively _____ into a medium in which it moves _____.
Refraction is the bending of the path of light as it passes across the boundary between two media. The direction of bending is dependent upon the relative speed at which light moves within the two media. The rules are:
- When light passes from a medium in which it travels faster into a medium in which it travels slower, the light ray will refract towards the normal line.
- When light passes from a medium in which it travels slower into a medium in which it travels faster, the light ray will refract away from the normal line.
The diagram shows two media (shaded pink and yellow), a solid black boundary line, and an incident and refracted ray (red). The incident ray is the ray approaching the boundary. Upon crossing the boundary, the light might bend away from the normal; in such cases, the refracted ray would be oriented further from the normal line than the incident ray was. Or the light might bend toward the normal line; in such cases, the refracted ray would be the ray which is closest to the normal line. Determine which way light has bent and then use the Know the Law section to answer the question.
