This week at the Young Einstein Club we were learning about how detergent weakens the surface tension of water by separating water molecules. This is the principle that is used to clean dishes – the detergent breaks the attraction of grease molecules for each other making it easier to wash away. We didn’t think an experiment that involved washing dishes sounded like much fun, so instead we used the detergent to separate water molecules behind a small floating cardboard boat. When the water molecules separated and mixed with the detergent molecules they pushed the boat forward.
Boats powered by soap may not be the solution to the energy crisis, but we had fun investigating how it works!!