1. The problem statement, all variables and given/known data The critical angle of refraction for calcite is 68.4 (degrees) when it forms a boundary with water. Use this information to determine the speed of light in calcite. 2. Relevant equations n=c/v n= Index of refraction c= Speed of light in a vaccum v= Speed of light in medium 3. The attempt at a solution I am looking for v so i rearranged the equation to look like this: v=c/n v= (3x10^8)/68.4= 4385964.91228 Is this right? Did the water have something to do with the equation? If not then could you please help, I have no idea how to work this problem otherwise.