Chapter 25 Vibrations & Waves

faster.

*A bow wave occurs when a wave source moves ___ than the wave it produces.

faster; sound.

*A shock wave occurs when an object moves ____ than the speed of _____.

higher; lower.

*As a wave source approaches, an observer encounters waves at a ____ frequency. As the wave source moves away, an observer encounters waves with a ___ frequency.

disturbance.

*The energy transferred by a wave from a vibrating source to a receiver is carried by a ___ in a medium.

length; acceleration.

*The period of a pendulum depends on only the _____ of the pendulum & the _____ of gravity.

vibrates.

*The source of all waves is something that ____.

electromagnetic waves; transverse.

*Waves in the stretched strings of musical instruments and the ___ that make up radio waves and light are ____.

speed of a wave.

*You can calculate the ___ by multiplying the wavelength by the frequency.

sound waves.

*___ are longitudinal waves.

interference patterns.

*____ occur when waves from different sources arrive at the same point-at the same time.

sine curve.

A ___ is a pictorial representation of a wave.

standing wave.

A ____ forms only if half a wavelength or a multiple of half a wavelength fits exactly into the length of the vibrating medium.

long; longer; shorter. slowly.

A ____ pendulum has a _____ period than a ____ pendulum. The longer pendulum swings back and forth more ____ -less frequently-than a short pendulum.

red shift.

A decrease in the frequency of light is called a ___, referring to the low-frequency, or red, end of the color spectrum.

wave.

A disturbance that is transmitted progressively from one place to the next with no actual transport of matter is ___.

vibration.

A repeating *back-and-forth* motion about an equilibrium position is a _____.

three-dimensional

A shock wave is a ______ wave that consists of overlapping spheres that form a cone.

stay in one place.

A standing wave is a wave that appears to _____-it does not seem to move through the medium.

speed.

After the ___ of the source exceeds the wave ____, increased _____ produces a bow wave with a narrower V shape.

blue shift.

An increase in the frequency of light is called a ____, because the increase is toward the high-frequency, or blue, end of the color spectrum.

increased; decreased; neutralized.

An interference pattern is a regular arrangement of places where wave effects are ____, _____, or _____.

cancellation.

Destructive interference is also called ___.

frequency = 1/period or period = 1/frequency.

Frequency and period are inverses of each other:

constructive interference.

In ____, the crest of one wave overlaps the crest of another and their individual effects add together.

destructive interference.

In _____, the crest of one wave overlaps the trough of another and their individual effects are reduced.

wave speed.

In the equation form, the relationship for wave speed is as follows: where v is ____, λ (Greek letter lambda) is the wavelength, and f is wave frequency.

shock wave.

It is not necessary that the moving source emit sound for it to produce a _____.

troughs.

Low points on a wave are called _____.

A. 200 m/s. B. 10 m/s. *C. 0.5 m/s.* D. 0.05 m/s.

MC: A certain ocean wave has a wavelength of 10 meters and a frequency of 0.05 hertz. What is the wave's speed?

A. longitudinal wave. *B. transverse wave.* C. standing wave. D. constructive wave.

MC: A wave created by shaking a rope up and down is called a ____.

A. increases. *B. decreases.* C. stays the same.

MC: As the sound of a car's horn passes and recedes from you, the pitch of the horn ____.

*A. higher.* B. lower. C. just the same.

MC: Suppose a bug is jiggling up and down and swimming towards you at the same time. Compared to the frequency at which the bug is emitting waves, the frequency of the waves reaching at you is _____.

A. 10 Hz. B. 1.0 Hz. C. 0.5 Hz. *D. 0.1 Hz.*

MC: The period of an ocean wave is 10 seconds. What is the wave's frequency? *Frequency = 1/Period*

A. movement of matter. B. harmonic object. *C. vibration.* D. region of variable high and low pressure.

MC: The source of nearly all wave motion is a ___.

330 m/s; 350 m/s.

Sound waves move at speeds of about ___ to ___ in air.

interference; transverse, longitudinal.

Standing waves are the result of ___. Standing waves can be produced in either ____ or ___ waves.

Doppler effect.

The *apparent changes in frequency due to the motion of the source (or receiver)* is called the ____. The greater the *speed of the source*, the greater the _____.

light.

The Doppler effect also occurs for ___.

changing pitch.

The Doppler effect is evident when you hear the _____ of a siren as a firetruck passes you. Police make use of the Doppler effect of radar waves in measuring the speeds of cars on the highway.

wavelength.

The ____ of a wave is the distance from the top of one crest to the top of the next one. Or, equivalently, the _____ is the distance between successive identical parts of the wave.

simple harmonic motion.

The back-and-forth vibratory motion (often called oscillatory motion) of a swinging pendulum is called ____.

speedboat knifing.

The familiar bow wave generated by a ______ _____ through the water is produced by the overlapping of many circular wave crests.

crests.

The high points on a wave are called ____.

frequency.

The number of vibrations an object makes in a unit of time is an object's ___.

antinodes.

The positions on a standing wave with the largest amplitudes are known as ___.

increased.

The result of constructive interference is a wave of __ amplitude.

sonic boom.

The sharp crack heard when the shock wave that sweeps behind a supersonic aircraft reaches the listener is called a ____.

medium.

The speed of a wave depends on the ___ through which the wave moves.

amplitude.

The term ____ refers to the distance from the midpoint to the crest (or trough) of the wave.

mass.

The time a pendulum takes to swing back & forth through small angles depends on the length of the pendulum- the ___ has no effect.

period.

The time of a back-and-forth swing of a pendulum is called the _____.

hertz (Hz).

The unit of frequency is called the ____. A frequency of one cycle per second is 1 ____.

inversely.

Wavelength and frequency vary ___ to produce the same wave speed for all sounds.

5.00m/1.25s = *4.00m/s.*

Waves in a lake are 5.00m in length and pass an anchored boat 1.25s apart. What is the speed of the waves?

Whenever the motion of the medium is at right angles to the direction in which a wave travels, the wave is transverse (*radio waves*). When the particles in the medium oscillate parallel to or along the direction of the wave rather than at right angles to it, the wave is longitudinal (*sound waves*).

What is the difference between a transverse wave and a longitudinal wave? Give examples of each.

medium; speed, wavelength; frequency.

Whatever the ___, the ____, ____, and ___ of the wave are related.

no transfer of matter.

When energy is transferred by a wave from a vibrating source to a distance receiver, there is ____ between the two points.

sound wave.

When someone talks to you from across the room, the __ is a disturbance in the air that travels across the room.

longitudinal wave.

When the particles in the medium oscillate parallel to or along the direction of the wave rather than at right angles to it, the wave is a ___.

bow wave.

When wave crests overlap at the edges and the pattern made by these overlapping crests is a V shape, the wave is called a ____.

out of phase.

When waves are ___, the crests of one wave overlap the troughs of one another to produce regions zero amplitude.

in phase.

When waves are ____, the crests of one wave overlap the crests of another, and the troughs overlap as well.

transverse wave.

Whenever the motion of the medium is at right angles to the direction in which a wave travels, the wave is a ___.

5,130 m/s.

Word Problem: A wave with a frequency of 60 Hz travels through steel with a wavelength of 85.5 m. What is the speed of this wave?

129 Hz; 0.00775 s.

Word Problem: Cicadas produce a buzzing sound that has a wavelength in air of 2.69 m. If the speed of sound is 346 m/s, what is the frequency of the sound produced by a cicada? What is its period?

Nodes.

___ are the stationary points on a standing wave.

interference.

___ is characteristic of all wave motion, whether the waves are water waves, sound waves, or light waves.