• Created by: Jaz Higgs
  • Created on: 04-06-14 14:34

Nature of Light Formulae

E= hf = hc/lambda 

h= plack's constant (6.63x10^-34) 

f- frequency (hz) 

lambda- wavelength (m) 

c- speed of light in a vacuum (3.00x10^8ms-1) 

eV= 1/2 mv2 

eV- electron volt 

m- mass 

v- velocity 

1eV- 1.6x10^-19J 

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Nature of Light Formulae 2

f= work function/h 

f- frequency 

h- planck's constant (6.63x10^-34) 

hf=1/2mv max2 + work function 

Radiation flux= power/area  


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A progressive wave carries energy from one place to another without transferring any material. 

For example: 

1) electron-magnetic waves cause things to heat up 

2) gamma rays knock electrons out of their orbit, causing ionisation 

3) wave power can be used to generate electricity


displacement- how far a point on the wave has moved from its undisturbed position 

amplitude- maximum displacement 

wavelength- the length of one whole wave, from crest to crest or trough to trough 

period- the time taken for a whole vibration 

frequency- the number of vibrations per second passing a certain point 

phase difference- the amount by which one wave lags behind another 

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Reflection, refraction and frequency

reflection- the wave is bounced back when it hits a boundary 

refraction- the wave changes direction as it enters a different medium 

frequency= 1/period 

the frequency is the inverse of the period. Get the units straight: 1hz= 1s^-1 


speed of wave =lambda (wavelength) x frequency 

v= d/t -> v=lambda/ 1/f 

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