# I Am Comfortable With Mathematical Equations

Looking for some help - with Snells law - I am given the angle of incidence and the angle of refraction. Do I have to sine these? Why or why not? I have to calculate the refractive index.
SolitaryElf
41-45, F
3 Responses May 7, 2015

I don't quite understand. In your post you say you have to calculate the RI. In one of the commentaries you say the RI is given at 1.5. So it is given and you have to calculate it at the same time? Doesn't make sense to me.

That's ok tkski Tutored me and I was able to figure it out :) Thanks tho !!!

1 (sin33) = X (sin 48)
1 ( 0.5446) = X (0.7431)
0.5446 = X (0.7431)
0.5446 / 0.7431 = X
0.7328 = X
0.5446 = 0.7328 (0.7431)
0.5446 = 0.5445
0.5446 / 0.5445
Refractive Index 1.0001

I have to disagree, your RI is 1/X ~ 1.36

Yeah you can disagree but it is correct according to my professor , my work and one who knows a hell of slot more than me about math.

The good thing about math is there is a right and a wrong and the answer is right.

So it seems I didn't fully understand the given problem.

I really lucked out when tkski messaged me I didn't understand it either - the poor man had to tutor me from scratch basically till I had my light bulb moment and it all clicked lol

So there is probably not enough in this post to understand the full question .. my bad .. but it is solved :)

Yeah, I am very late, but this made me curious. With the angles 33 and 48 I get an RI of 1.36, so this 1.5 totally confused me.

4 More Responses

it is solved tyyyyyyy tkski !!!!!

Yes, you need to take the sine of each angle. The ratio of the sine of the angles is inversely proportional to the indices of refraction

If one of the materials is air, you assume the index of refraction of air to be one, then you can solve for the RI of the other material.

yeah air is 1 my other is glass at 1.50.......
. the angle of incidence is 33degrees the angle of refraction is 48 degrees so is the following correct ?
.
1 ( sin 33) = 1.5 (sin 48) ......
.
so 1(5.7445) = 1.5(6.9282)....?..
.
5.7445 = 10.3923
.
??????
.

I thought the refractive index would be 1 number????or???

Hmmm... Does the problem give you the index of refraction of the glass as 1.5?

yes it does

Check your pm for my thoughts

2 More Responses