Light Sound and Waves

Reversing Glass

Enrichment Activity for 5-11 11-14

What you need

  • A glass of water
  • A piece of paper
  • A marker pen


  1. Draw a column of short arrows
  2. Hold the paper a little way behind the glass and look through the water at the arrows

Results and Explanation

The arrows should point in the opposite direction. The water acts like a glass lens, bending the rays of light and reversing the image of the arrows.

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can be analysed using Refraction Formation of Images
can be analysed using the quantity Focal Length Power of a Lens
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