A laser beam with vacuum wavelength 632.8 $\mathrm{nm}$ is incident from air onto a block of Lucite as shown in Active Figure 35.10 $\mathrm{b}$ . The line of sight of the photograph is perpendicular to the plane in which the light moves. Find (a) the speed, (b) the frequency, and (c) the wavelength of the light in the Lucite. Suggestion: Use a protractor.