Question Video: Know That the Image Appears to Be the Same Distance behind the Mirror as the Object Is in Front of the Mirror Science • Third Year of Preparatory School

Video Transcript

An object is located one meter in front of a plane mirror. Light from the object is reflected by the plane mirror that produces an image of the object. Which of the following correctly describes how far behind the mirror the image appears to be? (A) Less than one meter, (B) one meter, (C) more than one meter.

Let’s begin by drawing a sketch of this scenario. Say that here is a plane mirror seen from the side, and then here is an object. And the object is a distance of one meter from the mirror. Light from the object is reflected by the mirror. These reflected light rays, when traced backward, form an image. It’s the image of the object. Because the mirror is a plane mirror, the distance from the mirror to the image is the same as the distance from the mirror to the object. In this case, that’s one meter. For a plane mirror, it’s always true that the distance from the mirror to the object is equal to the distance from the mirror to the image.