Weird question (1 Viewer)

[M3riJaan]

hey all

Just had our physics trial, and we got this strange question about the particle and wave models of light

went something like:

Compare the wave theory of light to the particle theory of light in terms of explaining the differences between red and blue light

it was 4 marks, I could explain the wave bit, but i couldnt tell whether the particle theory referred to einstein's breakthrough or newton and aether

I cbf waiting until we the trials back, coz that's gonna be ages, so yeah, all you physics buffs, get back to me whenever

good luck with all your trials too!

 

[Gussy Booo]

Particles vibrate..........

Since it's light....they vibrate perpendicular to the direction of propagation.

That's as much as i've learnt from prelim. Can you take it from there?

Red and Bluelight have a difference in wavelength.....therefore...........

 

[blahblah111]

that refers to cathode rays and the experiments done with them
like the maltese cross, paddle wheel and them being deflected by magnetic and electric fields
then the stuff to do with the red and the blue light im assuming has stuff to do with hertz's experimant and the photoelectric effect and how if u shine different light colurs on a metal, then depending on its threshold frequency the electrons will be removed providing a current, which proves the particle nature of light (photons)

 

[Bernie Mac]

I dunno what this means to the question...but maybe you could go on about how light is red shifted or something? hence red to blue...I dunno
someone clarify this in terms of red and blue spectrums?

 

[darkchild69]

Waves:
- Talk about differences between red and blue light in terms of wavelength / frequency
- Can talk about intensity in terms of amplitude of the wave

Particles:
- Talk about difference in terms of energy (As attributed by E=hf)
- Can talk about intensity in terms of number of photons which pass a point each second

That's what i would do

 

[cybob101]

waves: frequency and wavelength c=f lambda light has properties prescribed by maxwell, shown by hertz
particles: photons --> energy per photon by e=hf intensity is number of photons here photoelectric effect. displacing electrons(einstein)

 

[mR sinister]

We had the same question in our trials, maybe it was the same?

My teacher after our results told us how to answer it.

He said you would first talk about the DIFFERENCES IN FREQUENCY in red/blue light.

You would use the formula C= frequency x Wavelength
so,
Frequency= C/ wavelength.

The Wavelength of red light = 700nm
the wavelength of Blue light= 400nm
This is something you should remember from the year 11 syllabus.

You would find the differences in frequency and compare them with relation to the classical wave model of light and the particle theory of light.

The main trick was to actually solve mathematically which i didn't do....
i only explained differences between the two models,
but to compare red/blue light you need mathematical calculations.