P ROC E DUR E
TEACHING CLUES AND CUES
A. Introduction
Ask students:
Q
What type of body wave did the Slinky exercise illustrate? (P
Students may be con-
fused by the array of
synonyms for P waves
and S waves. Help them
waves, also known as compressional waves or longitudinal waves)
Q
What is the other type of body wave? (S waves, also known as
waves or transverse waves)
B. Lesson Development
1. Give these instructions for demonstrating single shear waves (S
waves).
a. Place a band of bright colored tape halfway along the coiled
telephone cord. Place another band close to one end. Lay the cord
straight along a smooth surface. Have two students hold the ends of
the cord firmly so it will not move.
b. With plain masking tape, mark a 50-cm line perpendicular to one
end of the cord. Mark another line of the same length at the cord’s
halfway point, directly under the center band of tape. This will provide
you with a reference line.
c. Pick up the end of the rope at the center of the first perpendicular
tape line, then move your hand back and forth quickly along the
masking tape. As you expected, a wave travels down the rope (or
transmitting medium). Observe the motion of the colored tape while
waves are moving by. Students may take turns holding the ends of the
cord.
to understand that each term pro-
vides additional information about
one type of wave. P waves, or
primary waves, are also called
compressional waves and longitudi-
nal waves. S waves, or secondary
waves, are also called shear waves
and transverse waves. Both P and S
waves are body waves.
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