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There are two general classifications for waves—transverse and longitudinal. A toy spring, seen here, is perfect for demonstrating both types of wave motion. If you wiggle one end of the spring up and down, you will produce a transverse wave. Stretching it out and quickly compressing one end of it will generate a moving longitudinal wave. You will use a simulation to compare and contrast both types of waves.
transverse wave: a wave in which the medium moves at right angles to the direction of the wave
longitudinal wave: a wave in which the medium moves parallel to the direction of the wave
Open the Travelling Waves simulation. Select the “Transverse” option () and, click “Play.” Carefully compare the motion of the red dot and the motion of the wave itself. You will notice that these motions are not the same. The small red dot represents the medium through which the wave is passing. Spend a few minutes experimenting with different settings for both the wavelength and the frequency, and observe the behaviour of both the wave and the medium before attempting the following tasks.
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SC 4.
On the simulation, select the “Longitudinal” option (), and click “Play.” Once again, carefully compare the motion of the red dot and the motion of the wave itself.
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SC 5.
You have just described a key point about wave motion. The motion of the wave and the motion of the medium through which the wave passes are two distinct and different motions. These motions are summarized below.
The medium vibrates perpendicular (transverse) to the direction of the wave motion.
The medium vibrates parallel to the direction of the wave motion.
Does the medium travel as fast as the wave that passes through it? The simulation will now be used to compare the speed of the medium with the speed of the wave.
On the simulation, select the “Transverse” option (), and set the frequency to 0.5 Hz and the wavelength to 90.0 m. Carefully position the red dot at its lowest point. Do this by clicking “Play,” and then immediately click “Pause.” Use the “Forward” or “Back” buttons to move the dot to the desired position. Record the time shown at the top of the screen in the table below. Use the “Forward” button to move the dot to its highest point. Record the time again.
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total distance dot travels (1 grid square = 10 m) |
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start time (s) |
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end time (s) |
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time elapsed (s) |
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average speed of dot (in m/s) |
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SC 6.
total distance dot travels (1 grid square = 10 m) |
140 m |
start time (s) |
5.0 s |
end time (s) |
13.0 s |
time elapsed (s) |
8.0 s |
average speed of dot (in m/s) |
18 m/s |
Next, carefully follow a wave crest. Do this by clicking “Play” and then immediately clicking “Pause.” Use the “Back” button to take the time back to zero. Record the position of the first crest by counting the squares. Record the value in the table below. Click “Play” and then a few seconds later, while the crest is still visible, click “Pause.”
SC 7.
initial position of first crest (1 grid square = 10 m) |
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final position of first crest (m) |
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total distance wave travels (m) |
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initial time (s) |
0.0 s |
time at end (s) |
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time elapsed (s) |
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average speed of wave (in m/s) |
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SC 7.
initial position of first crest (1 grid square = 10 m) | 68 m |
final position of first crest (m) |
258 m (varies ) |
total distance wave travels (m) |
190 m (varies ) |
initial time (s) |
0.0 s |
time at end (s) |
33.0 s (varies) |
time elapsed (s) |
33.0 s (varies) |
average speed of wave (in m/s) |
5.76 m/s |
Your observations from this simulation show that the medium and the wave move in distinctly different ways, at different rates, and sometimes in different directions.
Watch this transverse vs. longitudinal video clip to compare the properties of longitudinal and transverse waves.
On the surface, water waves appear to be transverse waves. A closer look at the medium, however, shows that water waves are, in fact, neither transverse nor longitudinal. Watch this water waves video clip to observe the motion of a water medium when a wave passes by.
Read “Transverse and Longitudinal Waves” on pages 401 to 407 of your textbook to find out even more about the topic.
Remember to submit the answer to TR 2 to your teacher as part of your Module 8: Lesson 1 Assignment.
TR 2. Recall the earlier definitions given in this lesson for the terms listed in the table below. How could each of these terms be defined differently based on the type of wave? A quick diagram may help you explain these.
Term |
Transverse Wave |
Longitudinal Wave |
crest |
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trough |
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amplitude |
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wavelength |
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SC 8. Complete question 2 of “Practice Problems” on page 407 of your textbook.
SC 8.
v = 3.60 m/s
the time required to produce the pulse (t)
Use the formula to find the time. The length (l) is equal to Δd.
The time required to produce the pulse is 0.694 s.