Waves

gamma rays

(also called gamma radiation) penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei. --production of superhero HULK

wave energy

**Waves move energy not matter** All waves carry energy without transporting matter from place to place. •Molecules pass energy along to neighbor molecules who then pass energy to neighbor •All waves are produced by vibrations •Waves will travel as long as there is energy to carry

wave

A repeating movement or disturbance that transfers energy through matter or space.

sound waves

Compressional or Longitudinal Waves; Mechanical Waves because they require a medium to travel; Compressional waves formed when vibrating objects collide with air molecules.

parts of a compressional wave

Compressional waves have dense regions where the coils close together called compressions and less dense regions called rare factions.

electromagnetic spectrum

Electromagnetic waves carry transverse vibrations in electrical and magnetic fields -NOT vibrating particles. Electromagnetic waves do NOT need matter to travel through - they can travel through empty space ( a vacuum)

microwaves

Slightly higher energy than radio waves with higher frequency and shorter wavelengths. The microwave region of the electromagnetic (EM) spectrum is generally considered to overlap with radio waves.

amplitude of a compressional wave

The denser the compression the larger the amplitude.

amplitude of a transverse wave

The distance from crest or trough to the normal position.

parts of a transverse wave

Transverse waves have crests (the highest points) and troughs (the lowest points of waves)

X-rays

Ultra-high frequencies that can travel through matter, damage cells (bone images, radiation therapy)

Calculating wave speed

Wave speed (m/s) = frequency (Hz) x wavelength (m)v = f(ƛ)

amplitude

a measure of energy in a wave; the more energy a wave carries the greater the amplitude

diffraction

a solid object causes a wave to change direction and bend toward it.

resonance

ability of an object to vibrate by absorbing energy at its natural frequency

Doppler effect

apparent change in frequency of waves--Occurs when there is relative motion between the source of the waves and an observer **Either the SOURCE or the OBSERVER can be moving**

refraction

bending of wave caused by a change in its speed as it moves from one medium to another. Pencil in water looks broken due to refraction •The greater the change in speed the more the wave bends •Ex: Light and Sound waves

speed of sound

depends on the temperature and state of the medium the wave is traveling through. •Sound waves travel faster in liquids and solids than in gas. •The higher the temperature the faster the sound waves will move.

Wavelength

distance between one point on a wave and similar point nearest to it (crest to crest, trough to trough, compression to compression or rarefaction to rarefaction); The complete cycle of a wave; **The wavelength of a wave decreases as the frequency increases **

Ultraviolet Light (UV)

frequencies slightly higher than visible light (sunburns, Vitamin D production, fluorescent, materials absorb it, kills bacteria)

infrared waves

have slightly higher frequency than radio waves (remote control, warmth of fire, satellites)

radio waves

low frequency waves with a long wavelength (radio stations, radar)

compressional or longitudinal wave (sound)

matter in medium moves in the same direction that the wave travels; waves that require a medium (particles) to travel is called a mechanical wave.

transverse wave (electromagnetic - light)

matter moves back and forth at right angles to direction that the wave travels; All light waves travel as transverse waves including wavelengths not visible to the human eye. Not all waves needa medium to travel Light (electromagnetic) waves can travel through space.

medium

matter through which a wave travels A medium can be solid, liquid, gas, plasma or any combination.

frequency

number of wavelengths that pass a fixed point each second (hertz -Hz)

reflection

occurs when a wave strikes an object and bounces off of it - all types of waves can be reflected; (ex. Sound -Echo Light -Plane Mirror)

visible light

range of electromagnetic waves you can detect with your eyes (ROYGBIV - different colors have different wavelength)

law of reflection

the angle of incidence (i) of a wave is always equal to the angle of reflection (r)

interference

when two or more waves overlap and combine to form a new wave. constructive: waves add; destructive: waves subtract