Professional Development Course
for Teachers Using English
as the Medium of Instruction in Secondary Schools
(BWC031)
Class 2
23 April 2007 – 16 June 200
Module : Strategies for English Medium Teaching and
Learning
Module Code : ENG0146E
Learning Activity
Module Coordinator : Philip Hoare
Student : Loong Man Chun (s06712617)
F.4 / Wave nature of sound
page 1
Subject: Physics
Topics: Wave nature of sound – Reflection and diffraction
Level: S4
Learning objectives:
1. Content
By the end of this lesson students will be able to:
(i)
(ii)
(iii)
set up the apparatus to explore the reflection of sound waves
state the law of reflection
verify that the law of reflection for sound waves
2. Language
The main language objective(s) of this unit is to strengthen students’ speaking and
writing abilities. At the end of this lesson, students
F.4 / Wave nature of sound
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A. Investigation of reflection of sound wave (Pair work)
Metal plate
A


N

Long tubes
B
Student A holds a stop watch at end A of the long tube. Student B listens to the sound
produced by the stop watch at the end of long tube B. At the beginning of the
experiment, set the angle  equal to angle  with respect to the reference line N as
shown. Make your first observation. Then fix the tube A or the angle  but vary the
angle . Make several observations.
(i)
Can you hear the sound of the stop watch? Is it clear and loud? Describe your
observations to your partner.
Yes, I can. The sound is ___________ and ___________. As I decrease the angle  ,
the sound intensity ______________. As I increase the angle  , _______________.
(ii)
Tell your partner the position of tube B when you hear the sound with largest
intensity?
When I hear the sound with largest intensity, the angle  ____________________.
The sound wave emitted by the stop watch is reflected symmetrically by the
__________________ and is transmitted through the tube B.
F.4 / Wave nature of sound
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(iii) Recall the law of reflection you learnt in Optics. State the law of reflection.
The law of reflection states that the angle of incidence _____________________
_________________________________________________________________
(iv)
Discuss with your partner. Can we apply the law of reflection in sound wave?
From our observation in the reflection of sound wave, we found that when the
angle of incidence is equal to __________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
(v)
Write down your conclusion in complete sentences.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
B. Investigation of diffraction of sound wave (Pair work)
Student A and B stand about 4 to 5 m
from each other.
1. Student A talk to student B.
Plastic cone
F.4 / Wave nature of sound
2. Student A talk to student B with the
help of the plastic cone.
page 4
(i)
Is there any difference in these two cases? Which one is clearer and louder?
Describe your observations to your partner.
Yes, there is ___________________________________________. The sound is
___________ and ___________ in case ______. The sound wave goes straight
towards student B with the help of the ________________________
As shown below, water waves pass through two openings with different sizes.
Recall what you have learnt in ripple tank, discuss with your partner and sketch
the subsequent waveforms after the waves pass through the openings.
Large opening
Small opening
When the water waves pass through a small opening, the wave ___________________.
The energy of the wave distributes nearly _______________ degrees in front.
When the water waves pass through a large opening, the wave ___________________.
The energy of the wave distributes at a (larger / smaller) angle than the case of small
opening.
(You may consider the words like: spread out and concentrate)
(ii) Tell your partner, what do you call this phenomenon? (reflection / refraction /
diffraction / interference)
This is called ____________________________________
(iii) With the consideration of the water wave in the ripple tank, discuss with your
partner, do sound waves diffract?
F.4 / Wave nature of sound
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Sound waves behave like wave waves. They will undergo __________________.
When sound waves pass through a small opening, it _______________________.
The energy of the sound waves _______________________________________.
(iv)
Write down your conclusion in complete sentences.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
C.
Conclusion
Sound is a _____________________.
Sound demonstrates _____________________ and ________________________.
Sound reflects as sound waves meet an obstacle. It reflects with angle of incidence
___________________________________________________________________
Sound diffracts as sound waves change ___________________________________
when it passes through an opening.
F.4 / Wave nature of sound
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