(b) Are the observations made in Steps APl and AP-Z consistent with what the accepted values of the Indiees of Refraction indicate? Show why it was difcult to tell which way the ray was bent in Step APZ. Do this by calculating the reaction angle for an incident angle of40 for both Lucite and glass. Discuss the results of your calculation based on calculated reaction angles. Is the dietmrm observable? (c) In which medium among the three involved in Step BP4 does light travel the fastest: Lucite, glass, or water? Explain your reasoning. A. SHE\" '3 Law APl. Measure the angle of incidence and the angle of refraction for the semicircular Lucite disk. The best way to do this, as depicted in Figure 16.5, is to use a semirectangular plastic bottle, shaped like I .. ' (the cantedneck bottle is actually a discarded cell culture suspension ask from a biological laboratory experiment) to trace the path of the incident ray through the air. In order to see the laser beams better, you may need to request that the room lights be turned off. You will find it easier to measure the complementary angle, a) , rather than 6' . CAUTION: Do 110! move the laser or Lucite block during the time between making the incident and refracted beam measurements. First, use the ruler to nd the middle of the rectangular side of the Lucite semidisk and draw a line through this so that it intersects with the centers of the circles that form the two semicircular faces. Next, place the lateral side of the plastic bottle directly against the at face of the semidisk. Let the laser beam enter the plastic bottle at the angled side near the mouth of the bottle and aim it at the line marking the center of the rectangular side of the semidisk. If done correctly, the refracted beam trajectory through the semidisk should coincide with a radius from the center of the circle such that the beam emerges along the curved side of the semidisk perpendicular to that surface. Using the erasable marker pen, mark the points on the bottle and the semidisk where the beams traverse the interfaces. The ruler can be used to draw straight lines across the top faces of the bottle and semidisk joining the marked points on the interfaces. Finally, one can measure the respective complementary angles using the protractor. Figure 16.5 {a} Measuring the Angle of Figure 16.5 (11] Measuring the Angle of Refraction. Incidence. APZ. Place the triangular glass plate {etTectively, a two dimensional prism] on top of the rectangular Lucite block and position them against the Lucite semidisk1 forming a glassLucite interface as shown in Figure 16.6. Shine the laser beam through the glass into the Lucite as shown in Figure 16.6 and measure whether the beam is bent like Path A or Path B as shown. One case [A or B} will occur if Lucite has an Index of Refraction, \"Lucite that is larger than that of glass1 ngla. The other case (B or A) corresponds to mucus {I \"3135;. Again, mark the beams at the interfaces, then use a ruler to line up two points, and look at the third dot: You should use an angle of about 41]\" as your incident angte Figure 16.13 Two possible paths of the (despite the depiction in the illustration, the laser refracted beam. probably will not enter the triangular glass plate at a QUGangle with respect to the surface]. Note that Figure 16.6 shows an exaggerated version of the bending rays. It would be very difcult to tell which way the ray actually bends. Look at it quickly and individually write down your observation. You will need to answer why it is difcult to tell which path is taken by the refracted ray when you deal with the Report Questions at the end of this manual. Semi-Disk