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
How:
Procedure located here:
http://www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p010.shtml#procedure
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?
