waves test

Wave

A repeating disturbance or movement that moves energy through matter OR space.

Medium

 the matter (solid, liquid, gas) that mechanical waves travel through

2 types of mechanical waves

transverse and Longitudial

2 major categories

mechanical (need a medium) and electromagnetic (do not need medium)

Transverse wave

energy in the medium moves back and forth at right angles to the direction the wave travels 

Longitudinal wave

also known as compressional wave.  The energy moves back and forth in the same direction that the wave travels. 

Electro magnetic waves

DO NOT need a medium to travel through in order to transfer energy.  They can travel through a vacuum (space). Examples are microwaves, x-rays, ultraviolet light, visible light

Crest

high point in a transverse wave (above rest position)

Trough

low point in transverse wave (below rest position)

Wave length of transverse wave

distance from one point of a wave to the nearest point just like it (from crest to crest or from trough to trough)

Frequency

the number of waves that pass a fixed point each second

Amplitude

distance between a crest or trough and the position of the medium at rest

If wave length increases…

then the FREQUENCY decreases (the opposite is true too)

Compression

an area on the wave where the medium becomes more dense (squeezed tightly together)

Rarefaction

  an area on the wave where the medium is less dense

Wave length of compressional wave

distance from one point of a wave to the nearest point just like it (from compression to compression or from rarefaction to rarefaction).

Amplitude

 in a compressional wave, the amplitude depends on the density of the medium in the compressions and rarefactions.  (Very high amplitude compressional waves have very dense compressions and very low density rarefactions)

***the greater the amplitude, the more energy the wave carries 

***if you increase the AMPLITUDE of a compressional wave, the VOLUME gets louder

Reflection

The process by which a wave hits an object and BOUNCES off of it

Absorption

When a wave hits a material and it is not reflected back (instead it gets sucked in)

Transmission

To go through

How do electromagnetic waves move

Electromagnetic waves move in a transverse pattern

Requires a medium

Mechanical wave

Any type of matter that is disturbed by energy

electromagnetic

Amplitude

The amount of energy a wave has

Compresions

The denser part

Rare faction

Less dense part

Frequency

Pitch