Tranverse waves cause disturbances that move perpendicular
to direction of energy transport.
Longitudinal waves cause distrubances that move in parallel
to the direction of energy transport.
Mathematical representation of a wave.
How to generate a transverse wave with a certain frequency.
An ocean wave with a wavelength of 8 meters.
A longitudinal wave: the wavelength is the distance from
B to D (or C to E).
Wave Behavior
1. Huygen's Principle: All points on a wave act
as the source of a circular wave in all directions.
The total wave pattern is the sum of these Huygen wavelets.
2. Superposition: The existence of one wave does not alter
the other so that the
total disturbance of multiple waves at a certain location
and time is the sum
of all the disturbances caused by all waves at that location
and time.
3. Inverse Square Law: The amplitude of a wave diminisheswith distance.
The amplitude is inversely proportional to the square
of the distance from the origin.
This was discovered by Newton and is a consequence of
Huygen's principle.
4. Polarization: not applicable to sound waves....
whew!
5. Reflection: Waves are reflected at the same angle that
they are incident.
Example below has a 45 degree angle of incidence and
a 45 dgree angle of reflection.
6. Refraction: When a wave travels into medium with
different wave speed, the wavelength changes.
The result is a bending of waves between media that are
different.
7. Diffraction: Waves are bent by corners and edges of
media.
A consequence of Huygen's principle.
8. Interference: A consequence of superposition where
waves can combine
to strenghten or weaken their total disturbance.
Why we care about waves:
The Slinky Analogy
How to generate a sound wave.
How to detect a sound wave
Mechanical vibrations cause sound waves.
Light: Electromagnetic waves
Light is a tranverse wave
The electromagnetic spectrum.
Color is to light what pitch is to sound.
Doppler Effect: Caused by moving source of waves.
