6. Wavelength
Comment on the wavelengths of the plots.
Wavelength is decreasing from the red plot
to the purple plot.
7. Equation
Tranverse displacement of the
element of the spring located at x:
D(x) = A sin (kx) at
t=0
Where A = amplitude
k =
wave number
Wave number k = 2π/λ
-how often a waveform
repeats itself
(usually in rad/m)
8. Wave Numbers
Compare the wave
numbers (k) for
the waveforms on
the diagram.
A. k1 < k3 < k2
B. k3 < k2 < k1
C. k1 < k2 < k3
D. k2 < k1 < k3
1
2
3
9. Wave Numbers
Compare the wave
numbers (k) for
the waveforms on
the diagram.
A. k1 < k3 < k2
B. k3 < k2 < k1
C. k1 < k2 < k3
D. k2 < k1 < k3
1
2
3
Note: Wave number is defined by
how often a waveform repeats
over a wavelength
10. Traveling
Harmonic Waves
Harmonic WavesEquation: Replace x
with x-vt for
increasing x and x+vt
for decreasing x
D(x,t)=A sin (k(x-
vt))
or
D(x,t) = A sin
(k(x+vt))
v = wave speed
t = arbitrary time
11. Question
Which of the following equations
does NOT describe a traveling
harmonic wave?
A. D (x,t) = A sin (x - 9t - 10)
B. D (x,t) = A cos (x^2 - 9t)
C. D (x,t) = A cos (x - 9t - 10)
D. D (x,t) = A sin (x + 9t)
12. Question
Which of the following equations
does NOT describe a traveling
harmonic wave?
A. D (x,t) = A sin (x - 9t - 10)
B. D (x,t) = A cos (x^2 - 9t)
C. D (x,t) = A cos (x - 9t - 10)
D. D (x,t) = A sin (x + 9t)
not in
the form
x-vt or
x+vt
