SNC 2D
Lab Activity – Images in Plane Mirrors
Purpose:
To predict the image of an object reflected in a plane mirror.
Materials:
Ray boxes, rulers and protractors, plane mirrors, red plastic filters, white paper, pencils
Procedure:
Part 1:
1. Draw a line representing a mirror in the centre of a blank piece of paper
2. Set up a red translucent filter in a stand, and place it on the line you drew
3. Place an object (chess piece) in front of the filter some distance away, and mark its
location on the paper by tracing around it
4. Look through the front of the filter so that you can see the reflection of the object in
the plastic, and try to line up a second identical object behind the plastic so that the
image is superimposed on it; mark the location of the image on the paper
5. Measure the distance from the mirror to the object, and the mirror to the image,
and mark these distances on the paper
Question: What do you notice about the distances? What can you conclude from this?
Part 2:
1. Draw a line representing a mirror in the centre of a blank piece of paper, and place a
plane mirror on it
2. Draw an angled arrow in front of the mirror to act as the object (use a different
colour) and label the ends A and B
3. Using the narrow single-slit filter, shine a single ray at point A such that it is reflected
directly back along the incident ray; draw in a dotted line along this ray and arrows
to indicate its direction
4. Change the angle of the light through point A so that it is reflecting at a different
location on the mirror; draw in a dotted line for the incident and reflected rays, and
add arrows to show the direction of light travel
5. Repeat steps 3 and 4 for point B (it helps to use a different colour!)
6. Remove all objects from the paper and use a ruler to convert the dotted lines into
solid lines
7. Extend the reflected rays as dotted lines behind the mirror to locate the image
Question: Discuss the SALT of the image.