Tutorial: Drawing Ray Diagrams for concave mirrors
A method for finding the image of an object in a concave mirror is using ray diagrams.
This tutorial describes how you can find the image of an object located beyond the center of the
mirror:
1. Pick a point on the top of the object and draw to incident rays traveling toward the mirror.
Choose one ray so that it passes exactly through the focal point on the way to the mirror. Draw
the second ray such that it travels parallel to the principal axis toward the mirror. Place
arrowheads upon the rays to indicate their direction of travel.
2. Once the incident rays strike the mirror, reflect them according to the two rules of reflection for
concave mirrors, which you verified in Part A.
a. The ray that passes through the focal point on the way to the mirror will reflect and
travel away from the mirror parallel to the principal axis. (Use a ruler to accurate draw
the path).
b. The ray that traveled parallel to the principal axis on the way to the mirror will reflect
and travel through the focal point.
c. Place arrowheads upon the rays to indicate their direction of travel, and extend the rays
past their point of intersection.
