Wave Motion
Wave Motion - any disturbance propagating in a
medium such as string, air, etc.
Types of waves:
1. Mechanical waves
–waves are produced in materials such as solid, liquid and gas
2. Electromagnetic waves
- waves are produced in electric and magnetic fields and
can propagate even in vacuum or empty space.
Wave Pulse vs Wave Train
A wave pulse is a single disturbance
that propagates
A wave or wavetrain is a series of
periodic disturbances propagating
from one point to the next.
The term wave propagation refers to
the movement of waves
Classification of Waves
Waves may be classified as being progressive or stationary, we will only be
focusing on progressive waves
Progressive waves are those that transfer energy from one
point to the next
Classification of Waves
Waves may also be classified as been either transverse or longitudinal.
A transverse wave is one that has vibrations perpendicular to its direction of
propagation. https://www.youtube.com/watch?v=g8GcMn7K0u4
E.g light, radio, gamma rays and x-rays; waves
A longitudinal wave is one that has vibrations parallel to its direction of
propagation. https://www.youtube.com/watch?v=fMJrtheQfZw
E.g sound waves
Example using a Slinky
Wave Parameters
Transverse waves vibrate perpendicular to wave
energy movement. In mechanical transverse waves,
a medium is disturbed in an upward or downward
direction. The particles vibrate up and down returning
to their original position as the energy moves
perpendicular to that vibration forward.
Parts of a Transverse Wave
Equilibrium position
The equilibrium position of any wave is the middle point where
vibrations occur around.
Crest and Trough
A transverse wave has a top called a crest and a bottom called a trough.
Amplitude
Amplitude is the measurement from the equilibrium position to the top of
the wave. Amplitude can also be measured from the equilibrium position
to the trough. Both measurements will be the same.
If the amplitude of a light or sound wave increases the light
becomes bright and the sound becomes louder
Wavelength (𝜆)
Wavelength (𝜆)
It is the distance between successive points in a wave. The
distance from the equilibrium position to the crest, then to
the trough, and back to the equilibrium position is a standard
transverse wavelength (𝜆) measurement. Any crest to crest
or trough to trough would also be a wavelength.
Wave Phase
Please watch the following to understand wave phases.
https://www.youtube.com/watch?v=yKL6DjqAm3I
Period T and Frequency f
Period, T of a wave is the time for complete vibration,or The time it takes for two successive crests (one
wavelength) to pass a specified point.
Frequency, f of a wave is the number of complete vibrations per second, or the number of waves
that pass a point in a given amount of time. It's measured in hertz ((Hz)), which is named after
the German physicist Heinrich
https://www.youtube.com/watch?v=ys0mQbJYQjY
https://www.youtube.com/watch?v=tJW_a6JeXD8&t=2s
https://www.youtube.com/watch?v=aCu4VRKMstA
Period, T and Frequency, f of Waves
T must be in seconds (s) for to be in hertz (Hz). I the wave display above showing
a displacement-time graph for a wave, to be discussed further.
f= 1/T = 1/0.05s
f= 20s-1 or 20 Hz
Wavefronts
A wavefront is a line perpendicular to the propagation of a wave on which all
points are in phase.
Please watch the following video to get a general understanding of what it is.
https://www.youtube.com/watch?v=QRpV5pOMq34
General Wave Equation
The questions in the following will
be done in class.
Graph of Waves
Graph of Waves
Diffraction of waves
It is the spreading of waves as it passes an edge or goes through a gap
https://www.youtube.com/watch?v=7hNbcHmCey0
https://www.youtube.com/watch?v=6cNrh92kcRU
That is all…..
I know it feels like alot but you can do it…
