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Chapter 25 Review Vibrations and Waves Vibration: a wiggle in time Wave: wiggle in space and time (Hewitt, 372) 25.1 Vibration of a Pendulum 25.2 Wave Description Kaitlyn's heart beats 70 times per minute what is the period and frequency of her heart's beats? Answer: Frequency=70 Period= 1 minute In Pittsburgh there is an unsafe building that is 500 meters high. It oscillates in the wind with a period of 4.45 seconds. What is the frequency of the vibration? Answer: 1/4.45=.225 Hz 25.3 Wave Motion [] 25.4 Wave Speed 25.5 Transverse Waves · Transverse wave: Whenever the motion of the medium is at right angles to the way in which a wave travels. 25.6 Longitudinal Waves [] 25.7 Interference 25.8 Standing Waves 25.9 Doppler Effect [] 25.10 Bow Waves · Bow wave: The v-shaped wave produced by a moving object on a liquid surface faster than the wave speed. · Something can be supersonic if it travels faster than sound. · Bow waves are created by a speed boat going through the water and is made by the overlapping of many waves crests.  [] 25.11 Shock Waves · Shock wave: A cone shaped wave produced by an object moving at supersonic speed through a liquid. · Shock wave is produced by overlapping spheres that form a cone. · Sonic boom: The sharp crack heard when the shock wave that comes from a supersonic aircraft. Works Cited Hewitt, Paul G. __Conceptual Physics: With Expanded Technology The High School Physics Program__. New York: Addison-Wesley Pub (Sd), 1999.
 * Period: The time required for a pendulum to make one back and forth swing
 * Equation: t= 2Π √L/g
 * The longer the pendulum the longer the period, shorter the pendulum the shorter the period
 * Simple harmonic motion: The back and forth vibrating motion of a swinging pendulum.
 * Sine curve: A curve whose shape represents the crests and troughs of a wave.
 * Crest: One of the places in a wave where the wave is highest or the disturbance is greatest on the wave.
 * Trough: One of the places in a wave where the wave is lowest or the disturbance is greatest to the opposite crest.
 * Amplitude: The distance from the midpoint to the maximum crest of a wave or, from the midpoint to the minimum trough.
 * Wavelength: The distance from the top of one crest to the top of the next one.
 * Frequency: How frequently a vibration occurs
 * Frequency= 1/period
 * Period= 1/frequency
 * Examples: **
 * Hertz: A unit of frequency
 * Source of all waves is something that vibrates
 * When energy is transferred by a wave from a vibrating source to a receiver, there is no transfer of matter between the two points.
 * The energy transferred from a vibrating source to a receiver is passed by a change in a medium
 * The speed of a wave depends on the medium through which the wave moves.
 * Whatever the medium, the speed, frequency, and wavelength of the wave are related
 * Wave speed= frequency * wavelength
 * Low frequencies have long wavelengths and high frequencies have shorter wavelengths. 
 * Longitudinal wave: A wave in which the vibration is in the same direction the wave is traveling.
 * Sound waves are longitudinal.
 * Interference pattern: A pattern formed by the overlapping of two or more waves that arrive in the same place at the same time.
 * Constructive interference: The addition of two or more waves when wave crests overlap.
 * Destructive interference: Combination of waves where crest parts of one wave overlap through parts of another, resulting in a wave of decreased amplitude.
 * Out of phase: Term applied to two waves for which the crest of one wave arrives at the same place and at the same time that a trough of the second wave arrives.
 * In phase: Term applied to two or more waves whose crests and troughs arrive at the same place at the same time.
 * Standing wave: Wave in which parts of the wave remain stationary and the wave does not appear to be traveling.
 * Node: Any part of a standing wave that remains still.
 * Antinodes: The positions on a standing wave where the largest amplitudes are.
 * Doppler Effect: The change in frequency of a wave due to the motion of the source or of the receiver. (Hewitt, 383)
 * Blue shift: An increase in the frequency of light from source; called this because the increase is toward the high frequency, or blue, end of the color spectrum.
 * Red shift: A decrease in the measured frequency of light from a withdrawing source; called this because the decrease is toward the low frequency, or red, end of the color spectrum.
 * The greater the speed of the source, the greater the Doppler effect will be.
 * The pitch of the sound is greater when the source moves toward you, and less when it moves away.