PHYSICS LESSON PLAN
OBJECTIVES:
INSTRUCTIONAL
By the end of the lesson students should be able to:
1)
2)
3)
4)
Recognize that sound is a vibration
Identify that sound is composed of compressions and rarefactions
Recognize that sound requires a medium for transmission.
Deduce that sound travels differently in different media according to the
arrangement of particles
5) Compare the speed of sound as it travels through different media and the speed
of light as it travels through different media
6) Reason why sound can be heard underwater and by placing ears against the
ground.
7) Identify that sound does not travel through a vacuum.
EDUCATIONAL:
By the end of the lesson students will:
1.
2.
3.
4.
Develop communicative skills
Develop skills that enable them to work in a group
Develop analytical skills
Develop critical skills
THE PLAN:
1. Station Activity
Tell students to rotate different work stations which are equipped with the following:
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Drum + paper clips
Tuning fork and basin (trough) filled with water
Cantilever
Sonometer
Ask students to note their observations
Discuss observations as a class.
Questions to ask: (to include in w/s)
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What did you notice as you were carrying out the different tasks? (anticipate:
most students will deduce that vibrations are producing sound; idea of
movement/ disturbance)
What did you find common in all work stations?(anticipations: students will state
that there is noise, sound, movement)
What was produced when the drum/tuning fork was hit?(anticipations: students
will state that noise or sound was produced)
What energy transfer was taking place? (some form of guidance may be required
e.g what leads to a louder sound when drum is pounded. If guidance is not
needed then we anticipate that students will state the energy change: from
chemical to kinetic to sound energy)
Refer to the law of conservation of energy. How can the law be applied to what was
taking place in the workstations?
How can sound be defined? (anticipations: ideas will be pooled to come up with a
common official definition of sound)
Give definition of sound.
2. Slinky Demonstrations
Demonstrate longitudinal waves with slinky spring. Show the compressions and
rarefactions.
What do you think is being compressed as sound s travelling through air and different
media? (Anticipations: some students may deduce air particles are being compressed if
not, they will be further led to arrive to this conclusion)
Demonstrate transverse and elicit from students if we had transverse waves in the
workstations. Follow by distinguishing between longitudinal and transverse waves
(anticipations: students will deduce that the sound produced was longitudinal but will
not realize that the vibration in the drum is transverse)
Show Ruben’s tube video
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Why was fire used? (anticipations: to highlight compressions and rarefactions)
What does this video prove? ( anticipations: sound travels via compressions and
rarefactions)
Do you think that the speed of sound is going to be affected in different media
(i.e. solids, liquids and gases?)(anticipations: there may be some students who
will conclude that speed of sound varies in different media. If not all students
conclude this, then who understood will give their explanations to the rest of the
class)
3. Sound Travelling in Different Media
Give different scenarios and students state the reason:
Hidalgo movie clip
Image of person using glass to eavesdrop on neighbor
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What do these scenarios show us?(consolidate previous material)
Why do we hear the sound of speedboats when diving?(consolidate previous
material)
In which medium do you think sound travels the fastest? Gas, liquid or solid?
Why?(consolidate material)
(may include string telephone activity)
How are the particles of these different media arranged? How will these affect sound
transmission? (consolidate previous material)
Contrast with speed of light in a liquid and air (refraction) (anticipations: students may
find difficulties and so specific examples will be given e.g thunder vs lightning)
Turn W/S to work out.
4. Space Story
Describe spaceship video story (anticipations: most students will conclude that sound
will not travel through a vacuum; Students might ask whether shouting in space,
generates body vibration or whether they can hear themselves in space)
Bell jar demonstration:
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Why was no sound heard?(anticipations: consolidate learning)
What does this prove about sound? (anticipations: a medium is required)
In some instances, the bell sound is heard. Why is this so? (anticipations:
consolidation of material; students will give examples of sound travelling in
different places e.g cinemas, recording studios etc)