Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
31 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
Amplitude, Wavelength, Crest and Trough |
1) maximum displacement from undisturbed position 2) distance between same point on two adjacent waves 3) highest and lowest point on a wave |
|
|
|
Transverse |
Oscillations (vibrations) are perpendicular to the direction of energy transfer |
examples: all EM waves, ripples in water, wave on a string |
|
|
Longitudinal |
Oscillations are parallel to the direction of energy transfer |
examples: sound waves, shock waves (e.g seismic) |
|
|
Reflection. 2 kinds |
Specular = smooth surface, all waves go one direction Diffuse = rough surface, all waves go different directions |
Angle of incidence = Angle of reflection |
|
|
Refraction |
Less dense - denser: wave refracts towards normal, wave slows down Denser - less dense: wave refracts away from normal, wave speeds up |
Waves changing direction at a boundary |
|
|
EM wave spectrum trends radio -> gamma |
Increasing frequency and decreasing wavelength |
|
|
|
Radio wave |
Can be long or short wave Long wl diffract around curves surfaces, hills, tunnels Short wl reflect off ionosphere |
Short- Bluetooth, TV and FM radio |
|
|
Microwaves |
Mw ovens- different wavelengths to be absorbed by water molecules in food, transferring energy to the water & heating the food it’s quick |
Satellites- must be able to pass through earth’s watery atmosphere |
|
|
Infrared Radiationl |
Infrared cameras detect and monitor temperature and turns the IRR into electrical signals on a screen |
Can heat things up e.g food or electric heaters |
|
|
Visible light |
Optical fibres - carry data as pulses of visible light work through reflection |
|
|
|
Ultraviolet Radiation |
Fluorescent lights generate it, absorb and re-emit as visible light - energy efficient |
Produced by sun, gives a tan |
|
|
Infrared Radiationl |
Infrared cameras detect and monitor temperature and turns the IRR into electrical signals on a screen |
Can heat things up e.g food or electric heaters |
|
|
Visible light |
Optical fibres - carry data as pulses of visible light work through reflection |
|
|
|
Ultraviolet Radiation |
Fluorescent lights generate it, absorb and re-emit as visible light - energy efficient |
Produced by sun, gives a tan |
|
|
X-rays |
X-Ray photographs- rays can’t pass through denser materials (bones), can pass through flesh |
Radiotherapy - high doses kill all living cells |
|
|
Gamma rays |
Medical tracers - can pass out through body to be detected |
Radiotherapy - high doses kill all living cells |
|
|
EM radiation dangers |
Low frequency = low risk, don’t transfer much energy |
High frequency damage surface cells- sunburn, premature skin ageing, blindness and skin cancer |
|
|
Sound waves |
Caused by vibrating objects - pass through surroundings as a series of compressions and rarefactions |
They reflect (echo) and refract (enter denser, go faster) |
|
|
Ultrasound |
Frequency above 20000 Hz |
Uses: medical imaging (foetus scanning), industrial imaging, echo sounding (boats) |
|
|
P-Waves |
Longitudinal Travel through solids and liquids Faster than S-Waves |
|
|
|
S-Waves |
Transverse Can’t travel through liquids or gases Slower than P-Waves |
|
|
|
Seismic Waves |
Earthquakes produce them Some absorbed in earth, some refracted Seismologists measure where received, where not and time taken to be received |
|
|
|
Radiation dose conv |
Measure of the risk of harm from the body being exposed to radiation Depends on amount of radiation and type of radiation |
Measured in sieverts |
|
|
Convex lens |
Converges rays parallel to the axis to the principal focus |
|
|
|
Concave lens |
Diverges rays parallel to the axis so the rays appear to have come from the principal focus |
|
|
|
Describing ray diagrams |
Virtual/Real, inverted/upright, larger/smaller |
|
|
|
Colour of opaque objects |
The strong reflected wavelengths. Other wavelengths are absorbed |
They don’t transmit light |
|
|
White & Black objects |
White reflect all wavelengths Black absorb all wavelengths |
|
|
|
Transparent & translucent object’s colour |
Related to wavelengths it transmits and reflects |
They can transmit light |
|
|
Colour filters |
Only allow wavelengths of their colour through The rest are absorbed |
|
|
|
Black body objects |
Absorb all radiation that hits it - no radiation is transmitted or reflected They are best possible emitters |
|
