Wave Study
Phrases that DEFINE the Amplitude of Transverse
1. The distance from the rest position to a trough or a crest 2. The maximum distance the particles of a medium move up or down from their resting position. 3. The distance from the top of a crest or the bottom of a trough.
Electromagnetic Wave
A Wave that does not need a medium to travel (like a sun or sound wave)
Sound
A disturbance that travels through the medium. It is a longitudinal wave that depends of the elasticity, the density AND the temperature of the medium. The greater the intensity, the louder the wave. It is measured in decibels (dB).
Medium
A medium is a material in which a wave travels through (it can be a solid, a liquid and a gas)
Vibration
A repeated back-and-forth or up-and-down motion.
What is a wave?
A wave is a disturbance that transfers energy from place to place.
What are the basic properties of waves?
Ampltitude Wavelength Frequency Speed
Info on Sound Waves
Frequency- vocal cords determine this Pitch- High or low, depending on your frequency Resonance- the frequency of sound waves= the object's natural frequency (vibrations)
Formula to find frequency
Frequency= Speed/Wavelegnth THIS YOU CANNOT CHANGE
Speed
How far the wave travels in one unit of time.
The Unit used to measure the frequency
Hz (hertz)
If you. . .
If you increase the frequency of a wave and the speed stays the same, the wavelength must decrease.
The frequency is one wave per second
If you make one wave pass every second what is the frequency?
Wavelength
It is the distance between two corresponding parts of a wave.
The Amplitude of a wave is the direct measure of what?
Its energy
Formula to find speed
Speed= Wavelength X Frquency or Speed= Frequency X Wavelegnth
Energy
The ability to do work.
Amplitude
The amplitude is the maximum distance the particles of the medium carrying a wave move away from the resting position.
What is the Amplitude of a Longitudinal Wave?
The amplitude of a longitudinal wave is a measure of how compressed or rarefied the medium becomes.
What is the amplitude of water?
The amplitude of water is the measure of the particles BEFORE it was disturbed.
Doppler Affect
The apparent change in frequency of as a wave source moves in relation to the listener.
What Happens when a wave passed under a duck on a pond?
The duck moves back and forth slightly, but does NOT move with the actual wave.
Crests
The highest part of a transverse wave.
Troughs
The lowest parts of a transverse wave.
What does a rest position represent?
The motion before the medium was disturbed.
Frequency
The number of complete waves that pass a given point in a certain amount of time.
Rarefactions
The parts of a longitudinal waves where the particles are more spread out. (Back to the spring, the coils are farther apart now!)
Compressions
The tights parts of a longitudinal wave. (Think of a spring, these are the areas where the coils are closer together!!)
False diffract= bend/refract
The wave at point 3 moves into a different medium at an angle, the speed of the wave will change and the waves will DIFFRACT
Mechanical Waves
They are waves that require a medium to travel.
Examples
Transverse wave- wiggling a rope Longitudinal- a coil Surface- getting in a pool
False refract= defract
True or False? Change the capitilized word if it is wrong. The wave will REFRACT around the edges of the hole at point two.
True
True or False? The wave will REFLECT when it hits point A. Change the capitilized word if it is wrong.
True About Speed?
True- In a given medium and under the same conditions, the speed of a wave is constant. False: ALL waves travel at the SAME speed True: If the temperature and pressure of air changes, the speed of sound waves traveling through the air will change. True: Waves in different mediums travel at different speeds.
Formula to find wavelength
Wavelength= Speed/Frequency THIS YOU CANNOT CHANGE
What Causes Waves?
Waves are caused when a source of energy causes a medium to vibrate.
How are waves classified?
Waves are classified according to how they move.
Surface Waves
Waves that are combinations of transverse and longitudinal waves. They occur between 2 mediums (for example the two mediums could be water and air.) They move in circles.
Transverse Waves
Waves that move the medium at right angles to the direction in which the waves are travelling through. (Honestly I think of wiggly lines)
Longitudinal Waves
Waves that move the particles of the medium parallel to the direction in which they travel.
The ship bobs up and down.
What happens when a wave passed a ship at sea?
True or False?
When Waves Travel through a medium, they carry the medium with them. (FALSE)
Wavelength on a longitudinal wave:
You find the wavelength of a longitudinal wave by measuring the distance from one point to the next.
Compare- Longitudinal and Transverse
You should compare the crests on a transverse wave to the compressions on a longitudinal. You should compare the troughs on a transverse wave to the rarefactions on a longitudinal.
standing wave
a wave that APPEARS to be standing in ONE place
constructive interference
occurs when 2 waves have combined and made a wave with a larger amplitude
destructive interference
occurs when two waves have combined to make a wave with an amplitude that is equal to or less than zero amplitude
resonance
occurs when vibrations traveling through an object match the object's own natural frequency
diffractoon
the bending of waves around the edges of a barrier
interference
the effect two or more waves have on each other when they meet