Index of refraction and speed of light.

AI Thread Summary
Light travels at different speeds in various media, with the index of refraction affecting this speed. In a medium with an index of refraction of n=1.2, the speed is c1, while in a medium with n=1.6, the speed should be calculated as c2 = (1.2/1.6)c1, resulting in 0.75c1. However, this answer is not among the provided options, leading to confusion. It was suggested that if the indices were reversed, the answer would match one of the choices. The discussion highlights the importance of verifying problem details in physics calculations.
jakey
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Oh btw, this is not a homework question! just got it somewhere.
Light travels in a medium of n=1.2 at c1. what is its speed in a medium of n=1.6?

a)1.3c1
b)0.67c1
c)2c1
d)1.7c1
e)0.55c1

my solution:
using n=c/v, 1.2 = c/c1. also, 1.6=c/c2. c2= c/1.6. but c=1.2c1

So, c2=(1.2/1.6) c1=0.75c1. but it isn't in the choices. any help? thanks

also, do you know where i can find review materials for a-level physics (this is like UK based)? I am preparing for university entrance exams. thanks!:>
 
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Your reasoning is correct, the answer should be 0.75 c1.
Are you sure you copied all the numbers correctly?
 
CompuChip said:
Your reasoning is correct, the answer should be 0.75 c1.
Are you sure you copied all the numbers correctly?

i'm so sure that's why I'm so confused. however, 1.6/1.2=1.3 and its in the choices.
 
That's why I asked you to check the question.. if you'd interchange the 1.2 and 1.6, then the answer is there.
 
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