Super soapy boat

This science experiment uses the same principles as the tie dyed milk experiment we did several days ago.

You'll need:
cardstock or an index card
a sink or large rectangular baking dish
water
liquid dish soap

Cut the index card or cardstock into the shape of a boat, and add a small square notch in the center of the flat end. (See my example below)

Make sure your sink or dish is clean, then fill it halfway with water.

Place the boat gently on top of the water at one end.



Squeeze a few drops of dish soap into the space where you cut out the notch, and watch the boat zoom away!


The reason this experiment worked is because water molecules stick together very tightly and formed an invisible bond (called surface tension) that held the boat in place. Adding the dish soap broke the bond and allowed the boat to zoom ahead! The same thing happened with the tie dyed milk experiment -- the surface tension of the milk held the food coloring in place until the dish soap was added, breaking the bond.

As far as this experiment goes, the kids definitely liked the milk experiment better. The boat experiment was fun, but the boat got too soggy after sitting in the water for a minute and wouldn't zoom away again, so we could only do it once. Still really interesting though!