mocks - waves Flashcards
amplitude and wavelength
amplitude - distance vertically from centre line to top and centre of wave.
wavelength - stance from beginning of wave and goes through and up and down and then back to middle of wave on centre line
frequency of waves
number of waves passing a point per second
transverse wave
- PERPENDICULAR to direction of energy transfer
- vibrations up and down and travel side to side
longitudinal waves
- PARALLEL to the direction of energy transfer
- travel in the same direction as wave
3 wave transport
- absorbed (transfer energy to material)
- transmitted (pass through)
- reflected (…..)
6 features of ray diagram
- incoming ray
- reflected ray
- angle of incidence
- angle of reflection
- point of incidence
- normal
specular wave reflection
waves reflect in SINGLE DIRECTIONS by a SMOOTH SURFACE
diffuse wave reflection
waves reflect in SCATTERED DIRECTIONS by a ROUGH SURFACE (matt)
electromagnetic spectrum
- radio waves
- microwaves
- infrared
- visible light
- ultra violet
- x-rays
- gamma rays
what’s are the trends for the EM spectrum
increase in frequency
decrease in wavelength
refraction
- waves crosses boundary of materials and changes direction
- the waves speeds up or slows down depending on the DENSITY of the materials
- wavelength will change but frequency stays the same
optical density
how quick light travels through material
how are radio waves made
- oscillating electric and magnetic fields from AC (alternating current)
- attach transmitter to oscilloscope and detect by a receiver
how are radio waves used in communications
long waves - large distances around the earth
short waves - blue tooth
very short waves - TV, radios,
uses of microwaves
- satellites - pass easily through atmosphere
- ovens - absorb and heat molecules in food
uses of infrared radiation
- infrared cameras to monitor temps (the hotter the brighter)
uses of visible light
- optical fibres (high qualoty glass)
uses of ultra violet
- tanning - UV lamps (dangerous)
- florescence
uses of x-rays
- easily pass through flesh (dangerous in high dosages)
uses of gamma rays
medical tracers - injected into body to trace isotopes
infrared radiation practice results
- back matt - best surface to absorb and emit radiation
- this is because they can absorb all wavelengths of light and convert them into heat
the earths temperatures
- day - lots of radiation absorbed from sun = hot
- night less absorbed = cold
what’s is black body radiation
an object that absorbs all radiation (none is reflected or transmitted)
ultrasound
- electrical devices made to produce electrical oscillations in a range of frequencies
- these are converted to produce sound waves which are beyond the range of human hearing
how is ultrasound used in medical imaging
pre - natal scanning
1. ultra sound waves pass through body - some detected and some pass back
2. timings of this echo and computers produce video images of foetus
P-waves and S-waves
P-waves (INSIDE EARTH)
- longitudinal
- solids and liquids
- fast
S-waves (INSIDE EARTH)
- transvers
- only solids
- slow
