A sheet of plastic, n = 1.5, 25 mm thick is used in a bank teller's window. A ray of light strikes the sheet at an angle of 45°. The ray leaves the sheet at 45° but at a different location. Use a ray diagram to find the distance between the ray that leaves and the one that would have left if the plastic were not there. mm
The answer is 8.228557704 mm. For any procrastinators..
I think you will need a calculation to find a solution to this problem: The incident ray if it were to travel through the plastic without being refracted would emerge 25mm from the normal Use Snell's law to find the angle of refraction with the plastic present sin i / sin r = 1.5 So sin r = sin i /1.5 sin r = 0.7071 / 1.5 = 0.4714 Hence r = 28 degrees (angle of refraction inside the plastic) If the ray emerges at distance x from the normal then x is found from the right angled triangle Tan 28 = x / 25 x = 25 x tan 28 = 25 x 0.5317 = 13.3 mm Difference is thus 25mm - 13.3mm = 11.7mm separation
David, your answer is incorrect according to the webassign. I'd done exactly that,
