7.1 General Wave Characteristics Flashcards
Transverse waves
the particles of the wave oscillate perpendicular to the propagation of the wave
longitudinal waves
The particles of the wave oscillate parallel to the direction of propagation
includes cycles of compression and refraction
examples of transverse waves
electromagnetic waves (including visible light, microwaves, and x-rays)
example of longitudinal waves
sound waves
what type of wave is visible light?
transverse waves
what type of wave are sound waves?
longitudinal waves
Wavelength (λ)
the distance from one maximum (crest) of the wave to the next
1/frequency
frequency (f):
1 / wavelength
the number of wavelengths passing a fixed point per second
Unit: hertz (Hz), or cycles per second (cps)
amplitude (A)
the maximum magnitude of displacement in a wave
“in phase” vs “out of phase”
if the crests of two waves pass the same point or line at the same time, they are in phase
Principle of superposition
when two or more waves overlap in space, the displacement of the resultant wave at any point is the sum of the displacements of the interacting waves
Constructive interference
the maxima of two waves (in phase) add together so that the amplitude of the resulting wave is equal to the sum of the individual amplitudes
destructive interference
a positive displacement of one wave is cancelled exactly by a negative displacement of the other wave
the amplitude of the resulting wave is zero
sound
a longitudinal wave transmitted by the oscillation of particles in a deformable medium
(sound cannot travel through a vacuum)
speed of sound equation
sound travels fastest through ____________ and slowest through __________
sound travels fastest through a solid with low density and slowest through a gas with high density
propogation speed (v) of a wave
formula
v = f λ
frequency x wavelength
period (T)
defintion
the number of seconds per cycle
the inverse of frequency
period (T)
equation
T = 1/f
(the inverse of frequency)
standing waves
can form when two waves of equal amplitude and frequency are travelling in opposite directions
different ampitudes, same phase
the nodes stay the same
kind of lookes like the waves are “flipping” above and below the line
travelling wave
have continuously shifting points of maximum and minimum displacement
amplitude of each particle is the same
size of the waves are the same and it looks like the whole thing is moving to the right as the nodes move
nodes
points with no oscillation (zero displacement)
points in the wave that remain at rest (amplitude = 0)
antinodes
points of maximum oscillation/displacement
first harmonic has the ——- wavelength
second harmonic has a —– wavelength, etc.
first harmonic has the longest wavelength
second harmonic has a shorter wavelength, etc.
how does the frequency between the first harmonic, second harmonic, third, etc.
frequency = cycles per second
the second harmonic will have twice the frequency as the first
the third harmonic will have 3x the frequency as the first
with each harmonic, the frequency ——– (increases/decreases)
increases
wavelength
tube open at both ends
L = length of pipe
n = harmonic
wavelength
tube closed at one end
L = length of pipe
n = harmonic
the harmonic (n) of a tube closed at one end can be….
any ODD integer
1, 3, 5, 7, etc…
this is a (open/closed) tube with a harmonic of —
this is an open tube with a harmonic of ONE
this is a (open/closed) tube with a harmonic of —
this is a Open tube with a harmonic of TWO
this is a (open/closed) tube with a harmonic of —
this is a open tube with a harmonic of THREE
this is a (open/closed) tube with a harmonic of —
this is a closed tube with a harmonic of ONE
this is a (open/closed) tube with a harmonic of —
this is a closed tube with a harmonic of THREE
recall: odd only for closed tubes
this is a (open/closed) tube with a harmonic of —
this is a closed tube with a harmonic of FIVE
recall: odd harmonics only for closed tubes
frequency
tube closed at one end
