Mission RM3 Plane Mirror Ray Tracing
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.
Along which line of sight must the eye look in order to see the image of the RED object?
Line of sight - it is a simple idea, but a very powerful idea once you get a grasp of it. To see anything, you must sight at the thing. To see an image, you must sight at the image. When you sight at the thing - whether the image or some other object - light from the thing travels along a line to your eye. Your eye and the thing you are looking at are two points on the line of sight along which you are looking.
The diagram shows an object (labeled), a mirror (diagonal line with yellow backing), an eye position and five different lines of sight. Each line of sight is labeled with a letter. You are to determine which is the proper line that a person must sight along when positioned at the eye location in order to view the image of the object.
As discussed in the Know the Law section, a person must sight at the image location in order to see the image. And when a person does sight at the image location, light will travel along that line of sight to the person's eye. This would be a quite an easy question if the image were shown; but it isn't. Fear not! If you were successful on the previous mission then you know that the image is located as far behind the mirror as the object is located in front of it. So use a measuring tool to determine the image location and then determine which line of sight is aligned with this location.
