Page 185 - text book form physics kssm 2020

Chapter 5
Waves
Figure 5.13 illustrates the amplitude, points in phase and wavelength of a transverse wave.
Identify several other distances that are equal to one wavelength.

X X λ X X Points in phase:
1 2 3 4
A X , X , X and X 4
2
1
3
Y Y Y
1 2 3
Y , Y and Y
1 2 3
Equilibrium Z , Z and Z
position 1 2 3
Z Z λ Z
1 2 3
Figure 5.13 A transverse wave
Figure 5.14 shows the points in phase and wavelength of a longitudinal wave. Can you
defi ne its wavelength in terms of compression or rarefaction?
λ λ
Points in phase:

P Q P Q P Q P P , P , P and P
1 1 2 2 3 3 4 1 2 3 4
Q , Q and Q
1 2 3
Compression Rarefaction Compression Rarefaction Compression Rarefaction Compression
Figure 5.14 A longitudinal wave

Figure 5.15 shows the profi le of a transverse Direction of propagation
wave at one instance and aft er a period, T of the
wave. In time, t = T, the wave profi le propagates
through the same distance as the wavelength, λ.

Wave profile at one instance
Distance travelled by
a wave profi le
From the equation, speed =
Time
λ
Speed of wave, v = λ
T
1
Wave profile after time, t = T
= T λ
1 Figure 5.15 A wave profi le
Frequency of wave, f =
T
Th erefore, speed of wave, v = fλ

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5.1.4
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