Mechanical Waves

mechanical waves

waves that require a medium through which to travel

transverse waves

A wave that causes a medium to vibrate at right angles to the direction in which the wave travels.

longitudinal waves

A wave in which the vibration of the medium is parallel to the direction the wave travels.

transverse wave picture

longitudinal wave picture

amplitude

Height of a wave from the rest point

frequency

the number of complete wavelengths that pass a point in a given time

wave speed

frequency x wavelength

wavelength

The distance between two corresponding parts of a wave

medium

Material through which a wave travels

reflection

The bouncing back of a wave when it hits a surface through which it cannot pass.

refraction

The bending of a wave as its speed changes when passing from one medium to another

crest

Highest point of a wave

trough

Lowest point of a wave

compression

The part of a longitudinal wave where the particles of the medium are close together.

rarefaction

a part in a longitudinal wave where the particles are spread apart

Hertz

Unit of frequency

diffraction

The bending of a wave as it moves around an obstacle or passes through a narrow opening

Interference

The interaction of two or more waves that combine in a region of overlap.

constructive interference

The interference that occurs when two waves combine to make a wave with a larger amplitude

destructive interference

The interference that occurs when two waves combine to make a wave with a smaller amplitude

Standing Wave

a wave that appears to stand in one place, and does not seem to move through a medium.

node

A point on a standing wave that has no displacement from the rest position

antinode

a point of maximum displacement midway between two nodes in a standing wave

decibel

a unit that compares the intensities of different sounds

loudness

A physical response to the intensity of sound, modified by physical factors

pitch

the frequency of a sound as a listener perceives it

Sonar

used to determine the distance between objects underwater

Doppler Effect

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

resonance

the response of a standing wave to another wave of the same frequency, causing an increase in amplitude

surface wave

A wave that travels along a surface separating two media

periodic motion

any motion that repeats at regular time intervals

period

The time required for one complete cycle of a periodic motion

sound waves

a longitudinal wave that we can hear consisting of compressions and rarefactions, which travels through a medium

intensity

the rate at which a wave's energy flows through a given unit of area