Question

When an object is moved a distance $x$ away from a plane mirror, the distance between the object and its image increases by $2x$. Give reason.

Answer 1

When an object is moved a distance $x$ away from a plane mirror, the distance between the object and its image increases by $2x$ because of the following reasons:

1. For plane mirrors, the object distance is equal to the image distance.
2. That is, the image is the same distance behind the mirror as the object is in front of the mirror.
3. For example, if we stand at a distance of$x$ meters from a plane mirror, we must focus at a location x meters behind the mirror in order to view our image.
4. In this case, the distance between the object and its image formed by a plane mirror appears to be $2x$ cm. So, the object distance will be $\frac{2x}{2}$ = $x$ cm.
5. Hence, the distance between the mirror and the object is x cm.