26.2
#14
Two rays of light converge toward each other
forming an angle of 27°. Before they intersect,
however, they are reflected from a circular plane
mirror with a diameter of 11 cm. If the mirror can be
moved horizontally to the left or right, what is the
greatest possible distance d from the mirror to the
point where the reflected rays meet?
Picture the Problem
: The image shows two rays that approach
each other at an angle of 27
°
. A mirror of diameter 11 cm is placed
in the path of the rays causing them to reflect before they intersect.
Strategy:
The distance
d
will be greatest when the rays are incident
at the edges of the mirror, 11 cm apart. The reflected rays and the
diameter of the mirror form an isosceles triangle. The distance
d
bisects this triangle forming two right triangles where
d
is one leg,
(11 cm)/2 is the other leg, the reflected ray from the mirror to the
point of intersection is the hypotenuse, and
θ
is 27°/2.
Use this
triangle to calculate the distance
d
.
Solution:
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '08
 Dr.G
 Physics, Light, triangle

Click to edit the document details