WEBVTT 00:00:00.062 --> 00:00:02.760 This is College Physics Answers with Shaun Dychko. 00:00:03.520 --> 00:00:06.085 A Light Ray is traveling from air into water. 00:00:06.337 --> 00:00:08.474 So it goes from a medium of index of refraction of 1.00 00:00:10.034 --> 00:00:13.131 to a medium with an index of refraction of 1.33 00:00:13.880 --> 00:00:19.731 and we can use Snell's Law to verify that the angle of refraction Theta two 00:00:19.971 --> 00:00:23.251 has to be less than the angle of incidence Theta One 00:00:23.462 --> 00:00:28.405 and so that means this upper path is what the light is going to follow. 00:00:29.062 --> 00:00:32.194 So n1 sine Theta One equals n2 sine Theta Two. 00:00:32.194 --> 00:00:39.691 That's Snell's Law and we can solve for Theta two by dividing both sides by n2 00:00:40.914 --> 00:00:44.942 and then we get sine Theta Two is n1 sine Theta One over n2 00:00:45.474 --> 00:00:48.720 and now since n2 is greater than n1. 00:00:49.245 --> 00:00:54.531 So the refraction of water is greater than the initial index of refraction in air. 00:00:55.142 --> 00:00:59.805 That means that this is going to be greater 00:01:01.130 --> 00:01:05.737 sorry, this is going to be less than sine Theta One 00:01:05.965 --> 00:01:09.091 because sine Theta One is getting multiplied by a fraction is less than one 00:01:09.400 --> 00:01:11.782 because the denominator is bigger than the numerator there. 00:01:12.451 --> 00:01:15.982 So sine Theta Two is going to be less than sine Theta One 00:01:16.108 --> 00:01:20.514 since the denominator n2 is greater than the numerator factor n1 00:01:21.331 --> 00:01:24.342 and with sine Theta two being less than sine Theta One 00:01:24.600 --> 00:01:27.085 that means Theta Two is less than Theta One 00:01:27.908 --> 00:01:30.051 and that's true for this upper path.