Description of Interactive

Locating an Image Using a Convex Mirror

There are three rules for drawing light rays using convex mirrors:
1. A light ray directed parallel to the principal axis will reflect off the mirror away from the focal point of the mirror.
2. A light ray directed towards the focal point on the other side of the mirror will reflect off the mirror parallel to the principal axis.
3. A light ray directed towards the centre of the mirror (the vertex) will reflect at the same angle made with the principal axis.

NOTE:
The third rule simply follows the Law of Reflection: the angle of reflection of the reflected ray is equal to the angle of incidence for the incident ray.

Using these three rules, you will be able to find the image of the arrow that is focused in the mirror.

Question 1: Object begins farther away from the mirror.
Question 2: Object begins closer to the mirror.

Use the LOST acronym to characterize the images while answering the questions.


1. Object begins farther away from the mirror.

This is the question/answer icon. Questions

 
  1. Where is the image located?
    Answer

    The image is located behind the mirror, between the mirror and F.

 
  1. Is the image upright or inverted (upside down)?
    Answer

    Compared to the object, the image is upright.

 
  1. What is the size of the image compared to the object?
    Answer

    The image is smaller than the object.

 
  1. Is the image real or virtual?
    Answer

    The image is virtual because the extended virtual light rays intersect on the other side of the mirror.

 

 

2. Object begins closer to the mirror.

This is the question/answer icon. Questions

 
  1. Where is the image located?

    The image is located behind the mirror, between the mirror and F.

 
  1. Is the image upright or inverted (upside down)?
    Answer

    Compared to the object, the image is upright

 
  1. What is the size of the image compared to the object?
    Answer

    The image is smaller than the object.

 
  1. Is the image real or virtual?
    Answer

    The image is virtual because the extended virtual light rays intersect on the other side of the mirror.

In a convex mirror, the image characteristics will always be the same. When compared to the object, the image will always produce a smaller, upright, virtual image that is located behind the mirror between the mirror and its focal point F. The farther away you move the object from the mirror, the smaller the image appears.

Technically, only two light rays need to be drawn in order to see where they intersect. A third light ray is used to make sure that all three intersect at the same point. If they do not, a mistake has been made. 
This means in order to predict the location of an image, you need to follow only two of the three rules learned.