Job #1: Sally and Kenny go Wading

   Sally and Kenny are wading in 2-foot deep water. Sally shouts, "Watch out for that rock on the bottom."
   But, alas, Kenny stumbles and falls. "Eeeow," moans Kenny, "it looked like the rock was still 4 feet away!"
   Kenny, who is 4 feet tall up to his eyelashes, shouted "Double Curses on Willebrord Snell."

  How far from his feet was the rock actually, at the time when it appeared to him to be 4 feet away?
   (Hint: Above the water the light ray from the rock is actually coming into Kenny's eye from the direction it SEEMS to be coming from, but below the water it does not.)
   In the diagram, show where the rock is and where it appeared to be. Draw solid lines for the path of the actual ray from the rock to Kenny's eye. Label the angles, then calculate the unknown angle and all distances that you need to know.

Here is some information
that may be of use to you:

Index of Refraction
  (except where the
  index for glass
   is given more

Your Answer:________________

On to Job #2: The famous fishing pole paradox
On to Job #3: How a prism separates blue light from red light
On to Job #4: The World's First Camera, or, How the Human Eye Works
On to Job #5: The Telescope, or How the Dutch Lens Grinders Made Galileo Famous
On to the Telescope Lab: Take two lenses and make a telescope right there in the lab
Answers to "Job" problems
Back to Optics Main menu

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