posted by A very narrow beam of white light is incident at 4 on .
A very narrow beam of white light is incident at 40.40° onto the top surface of a rectangular block of flint glass 11.8 cm thick. The indices of refraction of the glass for red and violet light are 1.637 and 1.671, respectively.
Calculate the dispersion angle (i.e., the difference between the directions of red and violet light within the glass block)
okay I can get the dispersion angle using snell law...23.32 and 22.82.
then i am asked to get the width as the rays hit the bottom which I can get using geometry...tan 23.32 = x/ 11.8 and same for the other. answer is .122cm
Then I am asked the following:
When the rainbow-colored beam emerges from the bottom of the block, the exiting rays of light are once again parallel. Calculate the distance between the exiting red and violet rays (i.e., the thickness of the rainbow).