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.

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