Shared Flashcard Set

Details

chapter 17
Mechanical waves and sound.
32
Science
9th Grade
02/23/2009

Additional Science Flashcards

 


 

Cards

Term
Mechanical wave
Definition
a disturbance in matter that carries energy from one place to another.
Term

Medium

Definition

the material through which a wave travels.

 

-a mechanical wave is created when a source of energy causes a vibration to travel through a medium.

Term

Crest

Definition

the highest point of a wave

 

[image]

Term
Trough.
Definition

the lowest point of a wave.

 

[image]

Term

Transverse Wave.

Definition

a wave that causes the medium to viberate at a right angle.

 

[image]

Term

Compression.

Definition
an area where the particles are close together.
Term
Longitudinal Wave
Definition

A wave in which the vibrations of the medium travel in the direction of the wave.

 

[image]

Term
surface wave.
Definition
a wave that travels along a surface seperating to media.
Term
Periodic Motion
Definition
any motion that repeats in regular time.
Term
Frequency.
Definition

number of complete cycles in a given area.

Term
Hertz (Hz)
Definition
Frequency is measured in cycles per second or hertz.
Term
wavelength.
Definition

the distance between one wave and another cycle wave at the same point.

 -Increasing the frequency decreases the wavelength.

Term
Amplitude
Definition

the maximum displacement of the medium from its rest position.

-the more energy a wave has, the greater its amplitude.

Term
one end of a rope is vibrated to produce a wave with a wavelength of 0.25 meters. the frequency of the wave is 3.0 hertz. What is the speed of the wave?
Definition

wavelength=0.25m

frequency=3.0Hz

 

speed=wavelength x frequency

 

speed=0.25m x 3.0Hz

0.25 x3.0= .75m/s

Term
reflection
Definition

occurs when a wave bounces off a surface that i can not pass through

-reflection does not change the speed of the frequency of a wave, but the wave can not be flipped upside down.

Term

refraction

 

Definition

the bending of a wave as it enters a new medium at an angle.

-Refraction occurs because one side of the wave moves more slowly than the other side.

Term
Diffration
Definition

the bending of a wave as it moves around an obstacle or through a narrow opening.

-a wave diffracts more if its wavelength is large compared to the size of the opening on the obstacle.

Term
interference.
Definition

occurs when two or more waves overlap and combine together.

-Two types of interference are constructive interference and destructive interference.

Term
constructive interference.
Definition
occurs when two or more waves combine to produce a wave with a larger displacement.
Term
destructive interference.
Definition
occurs when two or more waves combine to produce a wave witgh a smaller displacement.
Term
standing wave.
Definition

a wave that appears to stay in one place.

      -a standing wave forms only if half a wavelength or a multiple of half a wavelength fit exactly into the length of the viberating cord.

Term
node.
Definition
a point on a standing wave that has no displacement from the rest point.
Term
antinode.
Definition
a point where a crest or trough occurs midway between two nodes.
Term

sound wave.

 

Definition

longitudinal wave--compression and rarefaction that travels through a medium.

-many behaviors of sound can be explained using a few properties-speed, intensity, loundness, frequency, and pitch.

Term
intensity
Definition
the rate at which a wave's energy flows through a given area.
Term
decibel (dB)
Definition

a unit that compares the intensity of different sounds.

Term
loudness
Definition
a physical response to the intensity of sound, modified by physical factors.
Term

pitch.

 

Definition
the frequency of a sound as you percieve it.
Term
sonar.
Definition
a technique for determing the distance to an object under water.
Term
Doppler Effect.
Definition

a change in sound frequency caused by motion of the sound source, motion of the listener, or both.

 -as a source of sound approaces the observer hears a higher frequency, when the sound source moves away, the observer hear a lower frequency.

Term
resonance.
Definition
the response of a stading wave to another wave of the same frequency.
Supporting users have an ad free experience!