Problem: Problem Can we make a boat that can propel itself without an engine using fuel?
Hypothesis: Hypothesis The boat will propel itself if it cause a chemical reaction on the water by putting things like soap at the back of the boat.
Background Research: Background Research Soap contains an ingredient called surfactant. Surfactant is a compound that weakens the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid.
Materials: Materials Cardboards 2L plastic bottle Liquid soap Liquid glue Paint Shampoo Ointment Tooth paste
Procedure: Procedure Make boats with the cardboards Put the 6 different materials (tooth paste, glue….) on the back of the boat. Cut the 2L bottle in to same halves. Fill a half piece with water. Put the boats on the waterway. Observe if the boats can propel themselves, and check their speeds
Results: Results Tooth paste Shampoo Liquid glue Liquid soap Ointment Paint Yes Yes No Yes No No 1. Did the boat propel itself? Tooth paste Shampoo Liquid glue Liquid soap Ointment Paint Speed 3.43cm/s 9.6cm/s 0cm/s 5.33cm/s 0cm/s 0cm/s 2. The speeds of the boats
Conclusion: Conclusion The boats with shampoo, soap, and tooth paste which contain surfactants could propel themselves. The front part of the boat where shampoo, soap, and tooth paste are not applied pulled the boat front because the back part’s surface tension was weakened. Our hypothesis was supported by the experiment.