You need: an empty juice carton, two small plastic safety mirrors, sticky tape, a ruler and a pencil. What happens: looking into the bottom window, you can see over a table or wall. Why: light reflects (bounces) off the top mirror down the tube, then off the bottom mirror into your eye. Each mirror is tilted at 45°, so the light turns a right angle twice. Submarines use periscopes to look above the water.
Work it out in your head or on paper, then tap your answer — or type it and press Check. Stuck? Press “Show me how”.
Right: 0 · Tried: 0
🏁 Lesson 28 test
20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.
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