Chapter 26: Refraction of Light: Lenses
Questions & Problems
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Example 26.1
An underwater diver sees the sun 50o above the horizontal. (a) How high (or what angle)
is the sun above the horizon to a fisherman in a boat above the diver? Hint: sum of
angles of a triangle is 180° (b) Which angle is larger, the incident or refracted angle
relative to the normal? Explain.
Example 26.2
An object is 15 cm in front of a converging lens with a focal length of 10 cm. Use ray
tracing to determine the location of the image. What are the image characteristics: (i)
real or virtual?, (ii) upright or inverted?, (iii) smaller, larger or same?, and (iv) the image
location?
Example 26.3
For each of these parts, (i) Calculate the image height and position. (ii) What are the
image characteristics? (iii) Draw a rough sketch of the ray trace diagram to verify your
results.
a. A 2.0-cm-tall object is 15 cm in front of a converging lens that has a 15 cm focal
length.
b. A 2.0-cm-tall object is 15 cm in front of a converging lens that has a 20 cm focal
length.
c. A 1.0-cm-tall object is 15 cm in front of a diverging lens that has a 20 cm focal length.