urgent help!!! (1 Viewer)

[thejesster]

Underwater is a bubble of air 10cm in diameter. you shine a torch beam of red light(650nm) at the bubble. What happens to the beam in the bubble and after the bubble? Design an experiment you could do in the school laboratory that could lead to an answer.

help me please.. is it possible to substitute the bubble for a glass sphere and shine a torch through that - or is that not right coz they have different index of refractions?... but then we can use calculations, non?... please help me!... im pulling my hair out trying to figure it out.

thanks

 

[k02033]

the bubble is actually an air pocket. so light goes from air into the water, refract towards normal, then goes from water into air pocket, and refracts away from normal. (assume it to have index of 1 just like air above water) then it goes from air pocket to water again, refracting towards normal.

 

[k02033]

 

[thejesster]

ahh.. i thought it might have to involve concave lens and what not.. but how exactly am i meant to produce an experiment to show this - shining a red light through a bubble is not easy. .. and why is it red light? why can't it be blue??

 

[k02033]

the frequency of the light is specified since the refractive index of any material is actually a function of the speed of the light in that material.
ie
prehaps i should mention this 1st..
the speed and of the light actually changes as it passes from one medium to another with a different refractive index, but its frequency remains the same. and the frequency is the only thing that determine which type of EMR it is, (red light blue light UV...) and not its wavelength.
so lower the wavelengh of the light the higher than refractive index it experiences in materials.
higher the n, the more bending the light experiences, and more the light slows down. this is the reason why glass prisms is able to split white light up into its more colourful components, (since each wavelength experiences a different n, hence they all refract differently, and thus split

 

[thejesster]

i seeeee. thank you for your help..
i guess now i have to rack my brain trying to think up a way i could do this in a laboratory!...