1. The problem statement, all variables and given/known data A light ray enters the plastic block in the illustration at an angle of 33.0° and then exits the opposite side. The long side of the block has a length of 0.670 m and its index of refraction is 1.70. For how much time is the light ray inside the block? https://www.physicsforums.com/attachment.php?attachmentid=15094&stc=1&d=1219187822 2. Relevant equations Snell's law: nisin[tex]\theta[/tex]i=nrsin[tex]\theta[/tex]r n=index of refraction [tex]\theta[/tex]=incident angle from normal n plastic=1.70 n air = 1.00 3. The attempt at a solution According to Snell's law: (1.70)*sin(33)=(1.00)*sin([tex]\theta[/tex]) 0.92588636=sin([tex]\theta[/tex]) arcsin(0.92588636)=[tex]\theta[/tex] = 67.8023923 degrees And the speed of light is 2.998*10^8 m/s. But after that I am not sure where to proceed! Can anyone help me figure this one out?