Boat and Soap

 

 -A bowl

 -A piece of cardboard

-A pair of scissors

 -Liquid soap

-Water

 1. Fill the bowl with water

 2. Create a triangle from paper and put it in the corner

 3. Place a drop of soap on your finger and put your finger in the water behind the cardboard triangle.

The cardboard triangle begins to move toward the opposite side of the vessel.

At the beginning of the experiment the cardboard surface tension is not moving because it draws in all directions. But the soap reduces the surface tension.