Sample Ray Tracing Problems
1. An object 1 cm tall stands 6 cm in front of a lens with a focal length of +2 cm.
a) Draw a ray diagram showing the image formed by this lens. The two foci of
the lens have been drawn in. From your ray diagram, estimate the
magnification (including sign) and the approximate distance of the image
from the lens
b) Now calculate these quantities. How well did you do?
2. A pair of mirrors have focal lengths of 3 cm and 6 cm respectively. The mirrors are
exactly 9 cm apart, so they have a common focal point as drawn. The optic axis
is drawn in as a dashed line. Twobv different incoming light rays are drawn. For
each of these incoming rays, show how the light is reflected after it bounces off of
each mirror. In other words, show as accurately as possible the direction of the
rays for each of two bounces.
4. A diverging lens and a curved mirror are arranged such that the focal point of the
mirror (P) coincides with one of the focal points of the diverging lens. One incoming ray
is parallel to the optic axis. It misses the lens, bounces off of the mirror, and then passes
through the lens. Show how its direction changes at each step. The other one is headed
straight for the far focus of the diverging lens. It passes through the lens, bounces off of
the mirror, and then passes back through the lens. Show how its direction changes at
each step.
2cm
6cm
2cm
6cm
3cm
9cm
P
