1. Topic-
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2. Content-
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| Waves transfer energy in predictable ways. Humans invent communication
systems that use waves to transmit information from one person to
another. |
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3. Goals: Aims/Outcomes-
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1.Students will be able to connect their knowledge of harmonic motion
to waves
2.Students will be able to differentiate between transverse and longitudinal
waves
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4. Objectives-
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Waves are a form of harmonic motion that moves. The length and speed
of waves can also be measured.
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5. Materials and Aids-
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-wave tank
-slinky or spring
-elastic cord
-Projector
-Doc Cam
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6. Procedures/Methods-
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A. Introduction-
| Do Now: Think back to what we discussed in our last class about
harmonic motion. Now think about going to the beach and seeing the
waves come in and crash on the shore. Do you think that those waves
are an example of harmonic motion? Why or why not? |
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B. Development-
Harmonic Motion → Waves: Have students look at a pendulum example.
As the pendulum is swinging, make a graph of the position of the pendulum
(graph will be wave-shaped). The axis is labeled R, C, L for right,
center, and left. Ask students"�what does this graph remind you of?
Waves of all different kinds are examples of harmonic motion.
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C. Practice-
Different Examples of Waves: Use wave tank, spring or slinky, and
elastic string to show different examples of waves at work:
Wave tank"�show both circular waves (start a ripple with your finger)
and straight waves (use a plastic clipboard or ruler to push water
across tank). Ask students to compare and contrast the two different
types of waves. Depending on class size, this will either be done
as a demo or as small group exploration.
Slinky"�as a whole-class demo, show both a transverse (wiggle the
Slinky up and down) and a longitudinal (push the Slinky back and forth
so it stays as level as possible) wave. Ask students to compare and
contrast the two.
Elastic string"� First show kids a "messy"� wave by not pulling
the string taut and wiggling one side up and down. Then pull the string
taut and flick it to show the wave moving down the string. Once you
have demonstrated, give groups a piece of string to explore with for
1-2 minutes.
Focus on the similarities between different types of waves (see movement,
repeated/harmonic motion) and the differences (up and down vs. straight
across the wave). Define the types of waves as a class and sort the
different examples we have seen into longitudinal and transverse waves.
Turn and talk"�what's the difference between transverse and longitudinal
waves? Students will jot down a quick note for each type of wave (i.e.,
longitudinal = parallel, transverse = perpendicular) to remind themselves
of the definitions
Call on kids to remind us about the harmonic motion vocabulary (frequency,
period, amplitude). Show students how this relates to frequency, wavelength,
and amplitude on a graph. Students will label the wavelength and amplitude
on the graph and find the frequency (total number of cycles, given
that the graph shows one second). Connect the terms back to the pendulum
graph (amplitude is how long it takes for the pendulum to fall from
its starting height to lowest height in the center, which is the same
thing on the graph; frequency is still how many cycles in a given
time frame; wavelength is the distance it travels in one cycle).
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D. Independent Practice-
Graph-based questions about frequency/wavelength/amplitude, reading
and questions about longitudinal and transverse waves.
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E. Accommodations (Differentiated Instruction)-
1. Definitions provided prior to the lesson with pictures to help
demonstrate meaning
2. Adapted reading questions for the independent reading
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F. Checking for understanding-
1. Vocabulary checks- gauge how well students are remembering the
different vocabulary
2. Walk around to each group during independent work time and ask
them to demonstrate the difference between longitudinal and transverse
waves on the slinky
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G. Closure-
1. How do waves demonstrate harmonic motion?
2.How do we measure the length and speed of waves?
Collect independent practice to collect data. |
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7. Evaluation-
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1.Building off this lesson, students will learn about the difference
between mechanical and electromagnetic waves. Students will apply
prior knowledge to these topics.
2.Students will be assessed via a quiz
3. Students will apply knowledge of waves to our wave challenge activity
where they need to identify different types of waves. |
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