Mirror Lab Results


The purpose of this lab was to have students find the image of an object in a plane mirror using the law of reflection.  A pin was placed 4 cm in front of a plane mirror.  A ruler was placed 5 cm to the left of the pin and sighted toward the image, and a line was drawn.  The ruler was moved another 3-4 cm to the left and sighted toward the image and a line was drawn.  The pin and mirror were then removed and the lines extended beyond the mirror.  Where they intersected was where the image was in the mirror.  The distance from the pin to the mirror and the image to the mirror were the same.  A normal was then constructed.

The second part of the lab involved setting up the mirror and drawing a triangle with points A, B, and C in front of the mirror.  A pin was placed in point A and two lines were sighted to the image.  This process was repeated for points B and C and the pin and mirror were removed.  All the lines were extended and a triangle of the image was constructed and measurements were made to compare it with the original.

The third part of this lab involved calculated the focal length of concave and convex mirrors.  Two meter sticks were arranged at an angle to each other with the concave mirror at the point.  The object was placed a certain distance away from the mirror and the screen was moved until a clear image appeared.  The focal length was then measured and observations of the image taken.  The mirror was then switched to a convex mirror, the process repeated, and the image observed.