A slab of Plexiglas $2.00 \mathrm{~cm}$ thick with index of refraction 1.51 is placed over a physics textbook. The slab has parallel sides. The text is at height $y=0$. Consider two rays of light, $\mathrm{A}$ and $\mathrm{B}$, that originate at the letter "t" in the text under the Plexiglas and travel toward an observer who is above the Plexiglas, looking down. Draw on the figure the apparent $y$ -position of the letter under the Plexiglas as seen by the observer. (Hint: From where in the Plexiglas do the two rays appear to originate for the observer? ) You can easily do this experiment yourself. If you do not have a block of glass or Plexiglas, you can try placing a flat-bottomed drinking glass over the text.