Surface Tension
Properties of Matter

Foil Boat

Enrichment Activity for 5-11 11-14

What you need

  • A piece of foil
  • Scissors
  • Washing-up liquid
  • A sink or bath


  1. Take your foil and cut a shape 4cm x 10cm. The shape should look like a house (or rectangle with a triangle on top) with the base of the house being the shortest side. From the base cut a slot with a circle on the top.
  2. Gently place your boat into a sink full of clean water.
  3. Carefully place a drop of washing-up liquid into the boat's hole.

Results and Explanation

The boat moves! Water molecules are attracted to each other, creating "surface tension". The soap disrupts the surface behind the boat but the molecules in front are still pulling together, so the boat is pulled forward.

Surface Tension
can be analysed using the quantity Force

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