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Periodic Wave Phenomenon. Kayde Ford Sean Esposito. Waves:. Waves- a vibratory disturbance that travels through a material or space [ex: sound, water waves, light, heat waves
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Periodic Wave Phenomenon Kayde Ford Sean Esposito
Waves: • Waves- a vibratory disturbance that travels through a material or space [ex: sound, water waves, light, heat waves • A wave may be longitudinal, transverse, or a combination of both, depending on the direction in which the medium vibrates in relation to the movement of the wave’s energy.
Waves & Energy • Waves transfer energy without the transfer of mass • Waves can be produced in two ways: • A. Vibration of Particles • Requires a medium for transfer • Mechanical waves Sounds Water Drops EX: Sound, Water waves, Spring Waves
Waves & Energy Cont.. • B. Small changes in the strength of an electromagnetic field • Requires no medium for transfer • EX: light, microwaves, x-rays • Electromagnetic Wave 1 • Electromagnetic Wave 2
In which direction will segment X move as the wave passes through it? • down, only • up, only • (3) down, then up, then down • (4) up, then down, then up
ANSWER: (4) Up, than down, than up
Pulses & Periodic Waves • 1. Pulse – single vibratory disturbance that moves from point to point • Medium only moves up and down
Pulses & Periodic Waves Cont.. 2. Periodic Wave – series of evenly timed disturbances in a medium Periodic Waves
D. Vibrations and Waves • Transverse Waves- vibrational disturbance which is perpendicular to the direction in which the wave travels • Unlike longitudinal waves, transverse waves can be oriented in many different planes. • Ex) water waves, seismic waves, electromagnetic waves (light, microwaves, radio waves) • Transverse waves
C. Longitudinal Waves- medium moves parallel to the direction in which the wave travels • ex) sound - Guitar String
Characteristics of Periodic Waves: • Speed- • Wavelength- • Frequency- • Period-(T) – • Amplitude- • Crest-
Characteristicsof Periodic Waves • Frequency (f) = # of Vibrations seconds = # of Cycles seconds = Hertz (Hz)
ANSWER: • 3 Cycles
Ex)10 cycles pass a fixed point in a wave train in 5 seconds. • What is the frequency of the wave?
F= # of cycles • f = 10 cycles = 2 cycles • F= 2 Hertz seconds 5 seconds 1 second
Sound, frequency is pitch. • Light, frequency is color. FUN FACT * The Human Ear’s Frequency Range is 20Hz-20,000Hz
Period 1 T = f Period : time for an entire wave cycle to pass a given point in a medium -determined by source of vibration not medium
Wavelength • distance between two consecutive points in phase • determined by medium • symbol λ = lambda
Amplitude • Is the maximum change in position of a particle from its rest position during a single vibration • Amplitude of a wave shows the amount of energy in the wave • Amplitude is a measure of loudness for sound and brightness for color • Amplitude
Phase "In Phase" (0°)– points on a single periodic wave that have the same displacement (from equilibrium position) and moving in the same direction Whole number of wavelengths apart A & E, A & I, A & M B & F, B & J, B & N
Phase "Out of Phase"– (1800) - same displacement from equilibrium position but going in a different direction ½, 1½, 2½ etc wavelengths apart A & C, B & D, F & H
Which2 points are in phase? C and F Name 2 points that are 180° out of phase? B and D E and G
QUIZquizQUIZ • quizquizquiz
quiz • __________________ a vibratory disturbance that travels through a material or space • __________________single vibratory disturbance that moves from point to point • _________________series of evenly timed disturbances in a medium • _____________= #vibrations/sec • _____________– distance between two consecutive points in phase • ___= 1/f
Periodic Wave Phenomenon By Danielle Daly and Steven Conte
the repeating and periodic disturbance which moves through a medium from one location to another is referred to as a wave. waves transfer energy, not matter.
Whether we recognize it or not, we encounter waves on a daily basis. Sound waves, visible light waves, radio waves, microwaves, water waves, sine waves, cosine waves, stadium waves, earthquake waves, waves on a string, and slinky waves and are just a few of the examples of our daily encounters with waves. In addition to waves, there are a variety of phenomenon in our physical world which resemble waves so closely that we can describe such phenomenon as being wavelike.
Categories of waves: Transverse and Longitudinal
Categories of Waves: Transverse: Longitudinal: • a wave in which particles of the medium move in a direction perpendicular to the direction which the wave moves. • a wave in which particles of the medium move in a direction parallel to the direction which the wave moves.
Amplitude: The maximum absolute value of a periodically varying quantity. Amplitude has the unit of the quantity that is changing (ex. displacement, pressure, field strength, etc.)
Period: the time between successive cycles of a repeating sequence of events. The SI unit of period is seconds. Formula: T= t/n (time per number of cycles)
F R E Q U E N C Y: • the number of cycles of a repeating sequence of events in a unit interval of time. • ƒ = n/t (number of cycles per time). • Frequency and period are reciprocals (or inverses) of one another. • The SI unit of frequency is the hertz.
Phase: stage of development of a periodic process; Si unit is the radian. Two points on a wave with the same phase have the same… Phase is an angular quantity: • quantity of disturbance (ex. displacement) and • rate of change of disturbance (ex. velocity). • Adjacent points in phase are separated by one complete cycle. • Adjacent points out of phase are separated by half a cycle.
Wavelengths measured between adjacent points in phase. SI unit of wavelength is the meter the distance between any point on a periodic wave and the next point corresponding to the same portion of the wave measured along the path of propagation.
the rate of change of distance with time • the product of wavelength and frequency for periodic waves. • frequency and wavelength are inversely proportional. • -Lower frequency waves have longer wavelengths. • -Higher frequency waves have shorter wavelengths. • the speed of a wave is sometimes known as its wave speed • the SI unit of speed is the meter per second [m/s].
Quiz! 1.What are the two categories of waves? 2.Do lower frequency waves have shorter or longer wavelengths? 3.What is the SI unit of frequency? 4.What is the formula for period? 5.What is displacement, pressure, and field strength and example of?
Bibliography http://paws.kettering.edu/~drussell/Demos/waves/wavemotion.html http://www.indiana.edu/~emusic/acoustics/amplitude.htm http://www.qrg.northwestern.edu/projects/vss/docs/Communications/2-how-are-frequency-and-wavelength-related.html