# Brewster's angle

question:

'light travels from ethanol into crown glass. what's the brewster's angle?' and what is the significance of this angle?'

so i have:
nr = 1.52 (crown glass
ni = 1.36 (ethanol)

so it's 1.52/1.36 tan-1 = 48.2 degrees?

and what is the significance of 48 degrees?

any help is appreciated.

~Amy

berkeman
Mentor
They're not asking what is the significance of 48 degrees. They're asking what is special about Brewster's angle. For example, what practical optical devices take advantage of the Brewster's angle phenomenon?

k.. just reading the question here, in my first post i just wrote the short version of the question. is says:

..."what is the significance of this angle of incidence?"

sorry for any confusion..

~Amy

Chi Meson
Homework Helper
The Brewster's angle is the angle of incidence at which some phenomenon is at its maximum. If you can find the formula, you should be able to find the phenomenon.

here's what i wrote:
Note: 0 = theta

'sin 0R = ni(sin 48.2)/nR
0R = 41.8 degrees

the angle of incidence is important because (0B = 48.2) + (0R = 41.8) = 90 degrees. the angle of 90 degrees indicates the reflected light is completely polarized parallel to the interface.'

~Amy