1. The problem statement, all variables and given/known data The index of refraction for blue light in plastic is 1.46 and for red light is 1.39. Determine the angular spread of the spectrum leaving the plastic block [presumably to air] for a beam of white light incident at angle of 45° to the plastic block. 2. Relevant equations n1/n2=sinI/sinR 3. The attempt at a solution They are asking for white light, but I am only given blue and red? Using Snell's law to find: Blue - 1.46/1=sin45/sinX sinX=0.48 X= 28.97 Red - 1.39/1=sin45/sinY sinY=0.52 Y=31.33 Is that right? Would blue would leave at 28.97° and red at 31.33°. What about white light? Thanks.