WAVES A wave can be described as a disturbancethat travels through a medium from one locationto another location. The repeating and periodic disturbancethat moves through a medium from one locationto another is referred to as a wave.
A pulse is a single disturbance moving through a medium from onelocation to another location.
A medium is a substance or material thatcarries the wave.A wave is a disturbance of a mediumwhich transports energy through themedium without permanently transportingmatter.
A transverse wave is a wave in whichparticles of the medium move in adirection perpendicular to thedirection that the wave moves.
A longitudinal wave is a wave in whichparticles of the medium move in adirection parallel to the direction that thewave moves.
A surface wave is a wave in which particlesof the medium undergo a circular motion.Surface waves are neither longitudinal nortransverse.
Parts of a transverse waveThe crest of a wave is the point on the medium that exhibits the maximum amount of positive or upward displacement from the rest position.The trough of a wave is the point on the medium that exhibits the maximum amount of negative or downward displacement from the rest position.
The amplitude of a wave refers to themaximum amount of displacement of aparticle on the medium from its restposition.The wavelength of a wave is simplythe length of one complete wave cycle.
Parts of a longitudinal waveA compression is a point on a medium through which a longitudinal wave is traveling that has the maximum density.A rarefaction is a point on a medium through which a longitudinal wave is traveling that has the minimum density.
The frequency of a wave refers to how oftenthe particles of the medium vibrate when awave passes through the medium.A unit for frequency is the Hertz(abbreviatedHz) where 1 Hz is equivalent to 1 cycle/second.The period of a wave is the time for a particleon a medium to make one complete vibrationcycle.A unit for period is second.
The speed of an object refersto how fast an object is moving andis usually expressed as the distancetraveled per time of travel. v =λf
Sample Problem:The water waves below are traveling along the surface of the ocean at a speed of 2.5 m/s and splashing periodically against Wilberts perch. Each adjacent crest is 5 meters apart. The crests splash Wilberts feet upon reaching his perch. How much time passes between each successive drenching?
1.Reflection is the bouncing of waves as it hits a boundary or a surface.A portion of the energy carried by the pulse is reflected and returns towards the left end of the rope. The disturbance that returns to the left after bouncing off the pole is known as the reflected pulse.
Notable characteristics of the reflected pulse include:• The speed of the reflected pulse is the same as the speed of the incident pulse.• The wavelength of the reflected pulse is the same as the wavelength of the incident pulse.• The amplitude of the reflected pulse is less than the amplitude of the incident pulse.
The angle of incidence is equalto the angle of reflection.
2. Refraction involves a change in the direction ofwaves as they pass from one medium toanother. Refraction, or the bending of thepath of the waves, is accompanied by achange in speed and wavelength of thewaves.
3. Diffraction involves a change in direction ofwaves as they pass through an openingor around a barrier in their path.
4. Wave interference is the phenomenon that occurs whentwo waves meet while traveling along thesame medium. The interference of wavescauses the medium to take on a shape thatresults from the net effect of the twoindividual waves upon the particles of themedium.
1.Constructive interference is a type ofinterference that occurs at any locationalong the medium where the twointerfering waves have a displacement inthe same direction.
2. Destructive interference is a type ofinterference that occurs at any locationalong the medium where the twointerfering waves have a displacement inthe opposite direction.
When two waves interfere, theresulting displacement of the medium atany location is the algebraic sum of thedisplacements of the individual waves atthat same location.
Standing Waves Wave pattern that is characterizedby points that appear to be standingstill, the pattern is often calleda standing wave pattern.