# Homework Help: Speed of light. I NEED HELP PLEASE!

1. Apr 23, 2007

### Bk8907

Speed of light. I NEED HELP!! PLEASE!

1. The problem statement, all variables and given/known data

The index of refraction of table salt is 1.54 . What is the speed of light in table salt?

2. Relevant equations

3. The attempt at a solution

I NEED HELP!

2. Apr 23, 2007

### Integral

Staff Emeritus
Can you post the forumal for index of refraction?

3. Apr 23, 2007

### Bk8907

n=c/v. there is the formula

4. Apr 23, 2007

### Integral

Staff Emeritus
So what is stopping you from getting the speed of light in salt?

5. Apr 23, 2007

### Bk8907

yah, i just figured it out. I didn't think it would be that easy to solve. ha ha

6. Apr 23, 2007

### Bk8907

new question though....

ok, so diamond has an index of refraction of 2.42. Suppose that a rectangular block of diamond is immersed in a tank of water and that a ray of light is passing through the dimaond makes an angle of incidence of 25 degrees in the diamond. What is the angle of refraction with the normal in the air?

How do I even start?