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# Refraction Q?

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1. Please can you help me answer this question? Can you tell me your method/ thought process?

Thanks.
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2. Refraction .pdf (171.2 KB, 28 views)
3. (Original post by Whosthat?)

Thanks.
(i) is the angle of incidence.
(r) the refractive angle.

Angle beside the 85 angle is 95 (85+95-180, or a straight line).

Ergo, in the triangle, 85+given angle (which is equal to 30) gives is 115.

The sum of all angles in a triangle =180 degrees.

Therefore, 180-115= 65

i =65

Then we use snells law.

Sine1 / Sine2

Where sine1 =is the angle in air or "not in a medium". So, the core is a medium.

N (refractive index) = Sine1/ Sine2.

We are told the refractive index (N) of "X" is equal to 1.46

Therefore 1.46 = Sin65 / Sin U

Multiply both sides by sin U

Sin U x 1.46 = sin65

Therefore

Sin U = sin65 / 1.46
4. (Original post by Whosthat?)

Thanks.
Use trig to work out i
5. (Original post by apronedsamurai)
(i) is the angle of incidence.
(r) the refractive angle.

Angle beside the 85 angle is 95 (85+95-180, or a straight line).

Ergo, in the triangle, 85+given angle (which is equal to 30) gives is 115.

The sum of all angles in a triangle =180 degrees.

Therefore, 180-115= 65

i =65

Then we use snells law.

Sine1 / Sine2

Where sine1 =is the angle in air or "not in a medium". So, the core is a medium.

N (refractive index) = Sine1/ Sine2.

We are told the refractive index (N) of "X" is equal to 1.46

Therefore 1.46 = Sin65 / Sin U

Multiply both sides by sin U

Sin U x 1.46 = sin65

Therefore

Sin U = sin65 / 1.46
Thank you!

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