Topic 4 - Waves Flashcards
I have become the embodiment of annihilation, the herald of oblivion
simple harmonic motion ( 3 things )
- Force is restorative
- Repetitive motion
- acceleration is proportional to displacement, but in the opposite direction
Phase Change
- radians
- cycles or fractions of period
- phi Φ
What can you get from : x-t graph
- frequency
- amplitude
- wave height
- v-t graph
- period
- NO WAVELENGTH
waves : mechanical (the types)
- needs a medium to travel (ie water or sound waves)
Transversal
* Particles move perpendicular to the propagation of energy
Longitudinal
* particles move parallel with the wave motion
* now there is rarefaction and compression present
* on x-t graph, peak is compression and valley is rarefraction
waves : electromagnetic
- no medium needed
- electric field is normal to the magnetic field
EMS Spectrium
wavelength
* violet -> Red
* violet = 400nm
*red = 700nm
Intensity (Equations)
Spherical Intensity (Equation)
What can waves do
reflect
* wave meeting boundary, and at least partially diverted backwards
- refract / transmit
- interfere (superposition)
- diffraction (single + double slit)
transmission / refraction (into more dense)
transmission / refraction (into less dense)
what it does: polarizer
- turns 360˚ light into planar (usually EMS light)
- turns I into 1/2 I
what it does: analyzer
- this is the one at an angle to decrease intensity
Malus’s Law
Intensity due to Polarizer (Flip)
Brewster’s Law
than the reflected light is plane-polorised
Snell’s Law
n1 sinθ1 = n2 sinθ2
Critical Angle
- no refraction
- all internal reflection
diffraction (single slit)
if slit is smaller than wavelength, or object is larger than wavelength
Christian Huggens found it out
Path Difference
If integer (x) path difference: maximum constructive interference
if x+0.5 path difference: maximum deconstructive
where are nodes and anodes
String Instrument
Closed Pipe
Flute
Open Pipe
Clarinet
one closed - one open
