1)why does speed of different colours same in vacuum, when their wavelenghts are different???2)what is the cause of dispersion????3)do light travels with same freq. in every medium????4)why doesnt air causes dispersion???5)when sound wave travels from 1 med. to another, what happens?????6)does its f andwavelenght change????7)why does diff. colours travel with diff velocitys in glass???PLS ANSWER THESE Qs WITH ELABORATED ANSWERS WITH THE CORRECT REASON<<< I LL SURELY APPROVE!!!

Dear student,

The amount of refraction of light at a boundary between two media depends on three things:

1. The nature of the media (embodied in a characteristic quantity called the index of refraction for a medium).

    

2. The angle of indidence for the light ray on the boundary.

    

3. The wavelength of light.

The dependence of refraction on the wavelength of light is called dispersion. This dependence has both positive and negative implications for astronomy. On the positive side, it is the basis for the prism and its ability to separate light according to wavelength; on the negative side, it is the source of chromatic aberration in optical devices (the failure of different wavelengths to focus at the same point).