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• A vibration is a repetitive or periodic motion back and forth that does not travel anywhere
• A wave is a periodic motion or disturbance that travels (the disturbance travels, not the material itself)
• A vibration example would be the guitar strings, a wave example would be the sound that travels from it
• Vibration and waves have periodic motions or disturbances
• Vibration does not propagate while waves do propagate
• Vibrations can happen without creating a wave, while waves are usually caused by a vibration
• Waves have a number of different properties that we can measure
• The wavelength of a wave is the distance between the parts of the wave that form a repeating pattern
• When the particles of a medium are displaced by a wave, their maximum displacement is called the amplitude of the wave
• In a transverse wave, points of maximum and minimum amplitude are called crests and troughs
• In a longitudinal wave, they are called compressions and rarefactions
• The distance between any two troughs or peaks is one wavelength
• A crest has maximum displacement, so it is displaced in the positive direction
• A trough has minimum displacement, so it is displaced in the negative direction
• The time it takes for a wave to complete one cycle is a period
• During one period, the wavelength travels a distance of one wavelength
• The frequency of the wave is how many wavelengths pass through a stationary point every second
• Wavelengths measured in Hertz
• The velocity of the wave, displacement over time
• The intensity of a wave is the rate at which it carries energy
• It is measured by finding the energy flow through a plane perpendicular to the wave's velocity
• Matter cannot overlap but waves can
• When two waves combine, they will exhibit superposition
• Destructive interference, the resultant wave has lesser amplitude than the individual waves
• Complete destructive interference, the resultant wave has zero amplitude
• Aligned waves are known as in phase
• Adding amplitudes of the same waves gives a resultant wave
• Adding opposite waves will result in a resultant wave of zero
• Opposite waves are out of phase
• Added out of phase waves will result in complete destructive interference
• Loose boundaries will reflect waves, while fixed boundaries will reflect and invert waves
• When waves reach a small gap, the bending of waves is called diffraction
• When a resultant wave has greater amplitude than the individual waves, this is called... constructive interference
• When a resultant wave has lesser amplitude than the individual waves, this is called... destructive interference
• When two waves meet in a medium, they pass through one another
• Passing waves continue on their paths
• During the period for which the waves overlap, their amplitudes add together
• Two waves moving in a perpendicular directions collide, briefly interfering with each other, and then continue on their way. What properties of the waves have changed?


  No properties of the waves have changed
• When two waves are overlapping, they are superimposed
• If the two waves are in phase, they will cause constructive interference