Monday, 1 July 2013

Research question

What I want to do:

Build a Raft Powered by Surface Tension

Where: Anywhere

When: It takes less than a week

Why:  It seems Interesting and it is manageable, feasible and Accessible.

Who: My group

Which:  Project is to Build a Raft Powered by Surface Tension


Procedure located here:

Materials Suggested:
  • Kitchen sponges (2)
  • Scissors
  • Ruler, metric
  • Transparencies, like those used on an overhead projector (2); available at your local office supply store
  • Marker
  • Toothpicks (1 box)
  • Tape
  • Large basin or sink
    • It should be large enough that the raft can travel a short distance within it.
    • Make sure it can be easily emptied, as you will be filling and re-filling it with fresh water often.
  • Water
  • Eye dropper; available at your local pharmacy
  • Liquid laundry detergent
  • Other substances to test their affect on water surface tension (try at least four):
    • Liquid hand soap
    • Toothpaste
    • Vegetable oil
    • Table salt
    • Corn starch, vinegar, or any other substances you want to test
  • Lab notebook

Terms and Concepts

  • Resistance
  • Surface tension
  • Molecule
  • Cohesive forces
  • Polar molecules
  • Hydrophilic
  • Surfactants

Questions to ponder about:
  • What causes the surface tension of water?
  • How do surfactants decrease the surface tension of water?
  • What do you think will happen to an object floating on the surface of water if the surface tension decreases?
  • What happens to water molecules when a drop of surfactant is put in the middle of them?



  1. If I increase surface tension the raft will move slower.

    1. The Controlled Variable:Surface tension
      The Independent Variable:Raft
      The Dependent Variable: Speed(Power)