01•Ch 1(F5 wave)
-
Upload
siti-salmah-erang -
Category
Documents
-
view
218 -
download
2
description
Transcript of 01•Ch 1(F5 wave)
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
1
Waves
1.1 Understanding Waves
Waves transferenergy
load
motor
(a) Vibration of a plastic bob on water
(b) Vibration of a loaded spring
(c) Vibration of a tuning fork(d) Oscillation of a simple
pendulum
Waves
Examples of vibration
Sound wave
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
2
Waves
1.1 Understanding Waves
Displacement Graphs of Waves
x/cm
T
T
- a - a
a
-xo
xo
T
t/sO
x/cm
a
-xo
xo
O distance/cm
Amplitude, a= maximum displacement, Xo
Amplitude, a= maximum displacement, Xo
Period, T= time taken for one complete
wave
Wave length, = distance travelled by a
complete wave
Frequency, f= number of complete waves
in one second
Velocity of wave, v
v = f = T
Displacement time Displacement distance
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
3
Waves
1.1 Understanding Waves
Type of Waves
compression
Direction of wave
Direction of vibration
C CR
rarefaction
Direction ofvibration
Direction ofpropagation
Direction ofvibration
Direction of wave
Direction of vibration
Direction ofpropagation
Direction of vibration
Direction of wave
Direction of vibration
Direction of wave
Direction of wave Direction of wave
Longitudinal wave
Water waves, light waves,electromagnetic waves, etc.
Sound waves, impulses along aslinky spring, etc.
Transverse wave
Directions of vibrating particles
Propagation of waves
Examples
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
4
Waves
1.1 Understanding Waves
X
X
X
y
y
y
turned180o
turned90o
polarised
polarised
no waveis formed
polarised wavesingle slit
Transverse wave
cross-slit
Xy
polaroidTransverse wave
Bright image
Less brightimage polaroidsunglasses
Too dark to see
Polarisation of Transverse Wave
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
5
Waves
1.1 Understanding Waves
Same frequency
Forcingagent
Forcedobject
Forcedvibration ofmaximumamplitude
Resonance
transferingenergy
Experiment to show resonance
A B C D EX y
X yA B C D E
Pendulums E and B havethe same naturalfrequency.
E vibrates with highenergy/amplitude.
Q
Q E loses energy to A, B, C
and D but B gains moreenergy.
B vibrates with highamplitude.B vibrates in resonance.
c
Q
weight
y
E
DC
B
A
X
Resonance
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
6
Waves
1.1 Understanding Waves
Without damping With damping
displacement/cm
t/s
displacement/cm
t/s
Compare
Constant Amplitude (energy) Decreasing
Constantperiod, T
frequency, fspeed, v
Constant
External damping Internal damping
Work done againstexternal force
Work done by vibratingatoms or molecules
Damping Oscillations
Loss of energy in damped oscillations
-
white paper
lamp
stroboscope
transparent tray
sponge
motor
drainhose
spherical bob
wooden barwater
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
7
Waves
1.2 Analysing Reflection of Waves
Proper adjustments
Constant water depth
Sponge
Speed of motor
Height of lamp
Stroboscope
to ensure constant speed/wavelength
to reduce reflection of water waves
to adjust the speed of water waves
for illumination and focussing of image
to freeze the wave pattern
Ripple Tank
plane wave circular wave
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
8
Waves
1.2 Analysing Reflection of Waves
to ensure constant speed/wavelength
to reduce reflection of water waves
to adjust the speed of water waves
for illumination and focussing of image
to freeze the wave pattern
-
1 2v1 v2 v1=
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
9
Waves
1.2 Analysing Reflection of Waves
Formation of Light Fringes of Water Ripple
2
waterripples
whitepaper
planes of light
acting as convex lens
Bright Bright Bright DarkDark
B B BD D
Bright fringes (image)
motor speed q f1q 1p motor speed p f2 p 2q
speed of wave isconstant
1 2v1 v2 v1=
Effect of Motor Speed
-
N (normal) N (normal)
incident waves i
reflected waves
reflected wavesr
reflected waves
i = r
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
10
Waves
1.2 Analysing Reflection of Waves
plane wave circular wave
plane reflector
concavereflector
convexreflector
Reflection of waves
N N
N N N N
F
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
11
Waves
1.2 Analysing Reflection of Waves
N N
N N
F
N N
reflected waves
N (normal) N (normal)
incident waves i
reflected waves
reflected wavesr
reflected waves
reflected waves
I Image
i = r
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
12
Waves
1.3 Analysing Refraction of Waves
Examples of refraction
Special case
wavelength is
speed v is also
direction of waves
Refraction of Waves
deep water
1
shallow water Deep
watershallow water
deep water
deep water
deep water
deep water
shallow water
shallow water
shallow water
v1
N
N
N
N
deepwater
deepwatershallow
water shallowwater
deepwater
deepwater
shallowwater
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
13
Waves
1.3 Analysing Refraction of Waves
deep water
12
v2
shallow water Deep
water
deep water
deep water
deep water
deep watershallow water
shallow water
v1
N
N
N
N
wavelength is decreased
speed v is also decreased
direction of waves does notchange : No refraction
deepwater
deepwatershallow
water shallowwater
deepwater
deepwater
shallowwater
F
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
14
Waves
1.3 Analysing Refraction of Waves
Refraction of Water Waves Near a Beach
A B C D
R
E F G
P
Q
X (cape)
Y (sea bay)
Depth of water Movement of water Amplitude ConditionPosition
P
Q
R
-
A B C D
R
E F G
P
Q
X (cape)
Y (Sea bay)
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
15
Waves
1.3 Analysing Refraction of Waves
Decreasing
Shallow
Deep
Converging at P
Spreading out
Straight
Highest
Low
High
Very rough
Calm
Rough
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
16
Waves
1.3 Analysing Refraction of Waves
Effect of Water Depth on Waves
motor switched on(vibrating) A B C water
waves
glass(transparent)
water
Position
A
B
C
Depth of water
3.0 cm
2.0 cm
1.0 cm
f
same
same
same
long
shorter
shortest
v
fast
slower
slowest
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
17
Waves
1.3 Analysing Refraction of Waves
same
same
same
long
shorter
shortest
fast
slower
slowest
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
18
Waves
1.4 Analysing Interference of Waves
Interference of Waves
Resultant amplitude
Resultantamplitude
a a
Water waves
a a2a
-2a
-a-acork a
-a a = 0cork cork
+
2a
a
a a
+-a
a = 0
Constructive interference Destructive interference
Standing waves
-
S1
S2
a
troughcrest AN
AN
AN
N
N
x
n = 0
n = 1
n = 1
D
Antinodal line
Nodal line
Constructive interference
Destructive interference
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
19
Waves
1.4 Analysing Interference of Waves
Vibrating
Interference of Water Waves
Production of coherent waves
Wave pattern of interference
Coherent waves
same frequency same amplitude same phase or constant phase
difference
= axD
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
20
Waves
1.4 Analysing Interference of Waves
Formula is where = wavelengtha = distance between two slitsx = distance between fringes
(n = 0 and n = 1)D = distance between the slits
and the screen
= axD
Youngs Double-Slit Experiment
colour filter
4 metres
double slit
screen
double slit
monochromatic light source
a
S1
S2
AN
AN
D
n = 2
n = 2
n = 1
n = 1
n = 0x
bright fringesscreen
dark fringes
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
21
Waves
1.4 Analysing Interference of Waves
(a) Single source small wavelength
(b) Single source bigger wavelength
Fringe patterns
S1
S1
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
22
Waves
1.4 Analysing Interference of Waves
(c) Double sources small wavelength
(d) Double sources bigger wavelength
Fringe patterns
S2
S2
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
23
Waves
1.5 Analysing Diffraction of Waves
Pattern of Waves By Diffraction
Short obstacle Long obstacle
Narrow slit Wide slit
Small Big
The bigger the wavelength, the better the diffraction
1 Straight obstacle
2 Effect of slit size ( stays the same)
3 Effect of wavelength (slit size stays the same)
Interference occurs nearer to the shorter obstacle
Diffraction angle 1 > 2 Narrow slit produces better diffraction
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
24
Waves
1.5 Analysing Diffraction of Waves
interferenceinterference
12
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
25
Waves
1.5 Analysing Diffraction of Waves
n = 2n = 1
n = 0n = 1
n = 2
screen
single slit
Monochromatic light source
For fringe n = o, : broadest and brightest As nq, width/brightness of fringe p
Diffraction of Light
single slit pin hole
Diffractioninstrument
Fringe patterns
n = 3 n = 2 n = 1 n = 0 n = 1 n = 2 n = 3
bright fringes
dark fringes
Characteristics
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
26
Waves
1.5 Analysing Diffraction of Waves
lamp set cylindrical
convex lens
bright fringes
XDiffraction grating3 000 lines cm1
D
x
Formula is n = order of diffraction = wavelength of lightd = distance between two slits in
a grating = angle of diffractionN = density of lines/slits
n = d sin
d = 1N
Monochromatic source White light source
Diffraction With Diffraction Grating
Fringe patterns
R R RV V V
spectrum of white light
white light
-
CRO
stopwatch microphone
60 510
15
20253035
40
45
5055
CRO
CO2microphone
Reflection
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
27
Waves
1.6 Analysing Sound Waves
Longitudinal wave Requires a medium for
transmission
Properties
Original sound
Amplitude,aincreased
Frequency, fincreased
Higher pitchHigher loudness
radio
Diffraction
Loud
weak
Loudweak
Loud
Interference
Sound Waves
PhenomenaRefraction
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
28
Waves
1.6 Analysing Sound Waves
transmitter
waterd
detector
fish
in out
probe
ultrasonic
foetus
1 Using sonar to detect a school of fish or to determine the depth of water
2 For diagnosis of the human foetus
Ultrasonic used is safe Size of foetus can be estimated Picture taken is not very clear
Some Uses of Sound Waves
Depth of water
d = v ( )
where v = velocity of ultrasonic in watert = to and fro time
t2
-
microphone
Audio wave Radio wave
low amplitude
high amplitude
carrier wave
carrier wave
lowerfrequency
higher frequency
AM modulator
Radio frequency generator
Amplifier Amplifier
FM modulator
AM waveform FM waveform
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
29
Waves
1.6 Analysing Sound Waves
Amplitude modulation (AM) Frequency modulation (FM)
Amplitude of radio wave ismodulated
Frequency of audio wave andradio wave is not changed
Subjected to loss andinterference
AM
Amplitude of radio wave isconstant
Frequency of radio wave ismodulated
Minimum loss Minimum interference
FM
CHARACTERISTICS
AM and FM Waves
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
30
Waves
1.6 Analysing Sound Waves
Radio wave
Audio wave Transmitter
Amplifier
Radio frequency generator
Modulator
Amplifier
Sateliteionosphere
Relay-station
Radio Localtransmitter
Satelitestation
TV Long-rangetransmitter
Radio Waves (AM/FM) Transmitter
Mode of Transmission
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
31
Waves
1.6 Analysing Sound Waves
Simple Receiver For Radio Wave
Block Diagram
Circuit Diagram
}
Functions
To receive all types of radio signals
To tune the receivers frequency In resonance with received frequency Amplitude of wave received is increased
To separate the audio frequency from the radio frequency
To filter and earth the radio frequency
To amplify the audio frequency
To convert audio signal into sound
Components
A : aerial
I : inductorC1 : variable
capasitor
D : diode
C : capacitor
T : transistor
L : loudspeaker
aerial
Loud speaker
AmplifierFilter for radio frequency
DemodulatorTuner
A
C1I
D
C
T
L
B
Earthed
-
Longman Project! Overhead Transparencies Physics Form
5
Pearson Malaysia Sdn.Bhd. 2007
CHAPTER
111
32
Waves
1.7 Analysing Electromagnetic Waves
Electromagnetic Waves
vertical electrical field
90o
horizontal magnetic field
Frequencyf/Hz
1023 1022 1021 1020 1019 1018 1017 1016 1015 1014 1013 1012 1011 1010 109 108 107 106 105
1014 1013 1012 1011 1010 109 108 107 106 105 104 103 102 101 1 101 102 103 104
Wavelength
Frequencyf/ Hz
Radio waves
Xray Visible light Microwaves
UHF VHF SW MW LW
Gamma raysUltraviolet rays
Infrared rays
SW MW LW
UHF VHF
/ m
Gammarays
Ultraviolet
Visiblelight
Micro-waves
RadiowavesX-ray Infrared
Electromagnetic Waves Spectrum
/ColorImageDict > /JPEG2000ColorACSImageDict > /JPEG2000ColorImageDict > /AntiAliasGrayImages false /CropGrayImages true /GrayImageMinResolution 1200 /GrayImageMinResolutionPolicy /OK /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 2400 /GrayImageDepth -1 /GrayImageMinDownsampleDepth 2 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict > /GrayImageDict > /JPEG2000GrayACSImageDict > /JPEG2000GrayImageDict > /AntiAliasMonoImages false /CropMonoImages true /MonoImageMinResolution 1200 /MonoImageMinResolutionPolicy /OK /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 2400 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict > /AllowPSXObjects false /CheckCompliance [ /None ] /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile (None) /PDFXOutputConditionIdentifier () /PDFXOutputCondition () /PDFXRegistryName () /PDFXTrapped /False
/Description > /Namespace [ (Adobe) (Common) (1.0) ] /OtherNamespaces [ > /FormElements false /GenerateStructure true /IncludeBookmarks false /IncludeHyperlinks false /IncludeInteractive false /IncludeLayers false /IncludeProfiles true /MultimediaHandling /UseObjectSettings /Namespace [ (Adobe) (CreativeSuite) (2.0) ] /PDFXOutputIntentProfileSelector /NA /PreserveEditing true /UntaggedCMYKHandling /LeaveUntagged /UntaggedRGBHandling /LeaveUntagged /UseDocumentBleed false >> ]>> setdistillerparams> setpagedevice