# chapter 25

tell me about red shift Red Shift is the Doppler effect in light when the object is moving away from me and there is a decrease in the frequency of the light because of the movement.
tell me about blue shift is Blue Shift is the Doppler effect in light when the object is moving toward me and there is an increase in frequency of the light because of the movement.
The apparent change in frequency due to the motion of the source or receiver is called the ______ Doppler Effect
A wiggle in time is a ______________ vibration
A wiggle in time and space is a ____________ wave
The time it take a pendulum to swing back and forth is called the _____ period
Does the period of a pendulum depend upon the mass of the pendulum? NO. The period of a pendulum depends upon the length of the radius
Name the two things the period of a pendulum depends upon. Length of the pendulum
Which as the longer period, a long pendulum or a short pendulum? Long pendulum
Back and forth vibratory motion is often called (two options) Oscillatory motion, simple harmonic motion
What are the low points in a sine curve called? trough
In a sine wave, what is the distance from the top of one crest to the top of the next crest called? lambda, wavelength
How often a vibration occurs is described by its _________________ frequency
Name the units of Hertz cycles/second
AM radio waves are measured in: kilohertz, 960 on the dial is
960,000 vibrations/second
A pattern formed by the overlapping of two or more waves that arrive in a region at the same time is called _________________________ interference pattern
When the crest of one wave overlaps the crest of another, their effects add together. This is called _____________________________ constructive interference
When the crest of one wave overlaps the trough of another, their individual effects are reduced. This is called _________________ destructive interference
What is the term applied to two waves for which the crest of one wave arrives at a point at the same time that a trough of the second wave arrives. Out of phase
What is the term applied to two or more waves whose crest (and troughs) arrive at a place at the same time so that their effects reinforce each other? in phase
The positions on a standing wave with the largest amplitudes are known as __________________ antinodes
In a standing wave, certain parts of the rope remain stationary. These are called ___________ nodes
A cone-shaped wave produced by an object moving at supersonic speed through a fluid is shock wave
What is a curve whose shape represents the crests and troughs of a wave, as traced out by a swinging pendulum that drops a trail of sand over a moving conveyor belt? Sine curve
A wave in which the vibration is in the ___________ direction as that in which the wave is traveling is called a longitudinal wave. same
A shock wave is produced by overlapping spheres to form a _______. cone
Why don't we hear a sonic boom from a slower than sound aircraft? because the wave crests reach our ears one at a time.
What is the name of the sharp crack heard when the shock wave that sweeps behind a supersonic aircraft reaches the listener? sonic boom
Standing waves are the result of _____________________________ interference
Standing waves can be produced in either _________________ or _____________________ waves. Transverse
longitudinal
Can a boat travel faster than the speed of the water waves? Yes. A boat can travel faster than a wave on the water.
A bow wave is a _______-dimensional wave two
A shock wave is a __________-dimensional wave. three
What are the units for lambda? distance, like meters
What does the symbol f stand for? frequency
What are the units of f? Hz or cycles/second
When a source moves toward you, do you measure an increase or decrease in wave speed? Neither. Wave speed remains the same. Frequency of the wave changes
Long wavelengths have ______________ frequencies. low
Short wavelengths have ___________ frequencies high
During a concert, sounds from all the instruments reach you at the same time. Why? ? Wave speed depends on the medium holding the wave. The sounds are all traveling through air so ? is constant for all frequencies and wavelengths.
Using the equation: ?=f lambda How can the ? be constant (in air) for all frequencies? f^ then lambdav fv then lambda^ frequency and wavelength vary inversely, giving a constant ?.
A metronome is set so that it makes 10 complete vibrations in 12 seconds. Find the frequency of the metronome. 10 vibrations/12 seconds = .833 Hz
While sitting on a pier, Carlos notices that incoming waves are 2 m between crests. If the waves lap against the pier every .5 seconds, find a.) the frequency and b.) the speed of the waves. Lambda = 2 m; t = .5 sec/cycle = period; f = 1/.5 = 2; ?=f lambda = (2 meters)(2 cycles/second) = 4 m/s
What is the wavelength of a 340 Hz sound wave when the speed of sound in air is 340 m/s? f= 340 Hz; ? = 340 m/s; ?= f lambda; so lambda = 340/340; lambda= 1 meter
Sound waves or percussion waves are what type of waves? Longitudinal waves
Can more than one vibration or wave exist at the same time in the same space? yes
When energy is transferred by wave from a vibrating source to a distant receiver, is there transfer of matter between the two points? No. The wave moves through the medium. Energy is transferred by a disturbance in the medium.
What does ? stand for? Velocity or wave speed
What is the frequency per second of a 100 Hz wave? 100 Hz = 100 cycles/second
The Sears Tower has a frequency of .1 Hz. What is its period? f = .1Hz = .1 cycle/second; period = 1/f = sec/.1 cycle = 10 seconds/cycle
FM Radio waves are measured in ________________ megahertz, 101FM is 101,000,000 cycles/second
The frequency of the vibrating source and the frequency of the _______ it produces are the same wave
The Doppler effect occurs for __________, ___________, and ________. light, sound, and time
A wave with vibration at right angles to the direction the wave is traveling is called a __________ ______ transverse wave
What is the name of the V-shaped wave produced by an object moving on a liquid surface faster than the wave speed? bow waves