4.2 measuring waves Flashcards
when would waves need to be measured
for example when intercontinental phone calls ae made the em waves are sent from ground transmitters to satellites where the are converted into electric waves and then back into sound waves when they hit another ground transmitter
need to measure the different types of waves at different stages to check that they aren’t being distorted
displacement definition
the distance and direction from its equilibrium position
defintion of amplitude
the maximum displacement of a vibration particle
e.g for a transverse wave this os the maximum height of a wave away from the equilibrium position
definition of wavelength
the least distance between 2 adjacent vibrating particles with the same displacement and velocity at the same time
definition of a complete wave cycle
from maximum displacement to the next maximum displacement
definition of a period of a wave
the time for one complete wave to pass through a fixed point
defitnion of the frequency of a wave
the number of cycles of vibrations of a particle per second, or the number of complete waves passing a point per second
what happens to the wavelength if the wave is of a higher frequency
the wavelength becomes shorter
what is the time taken for one cycle equal to
1/f
different calculation for wave speed
distance travelled one cycle / time taken for one cycle
lambda/ 1/f = f labda
wave speed =
frequency * wavelength
what is the phase of a vibrating particle at certain time
the fraction of the cycle that it has completed since the start of the cycle
what is the phase difference between 2 particles vibrating at the same frequency
the fraction of the cycle between the vibrations of the two particles measured in either degrees or radians
what does one cycle equal in degrees and radians
2 pi
360 degrees
the phase difference in radians =
2piD / lambda
