## Surface tension lid

**Lesson Objectives:**- Students will explore the idea of surface tension.
- Students will practice making free body diagrams.

**Let's Get Started!**

Have the students work in groups of 4-5. Each group should be given a mason jar with a hole in the lid, and various sized meshes so that they fit into the lid. Have the students choose a mesh size, place it in the lid, screw the lid on, and fill the jar up with water. Once the jar is filled, place a piece of cardboard on top of the jar, flip the jar and cardboard upside down together, and slide the jar off the piece of cardboard slowly. Have the students try this with different size meshes and jars, and take notes of what they observe. Have the students draw a diagram of the experiment and draw an arrow in the direction gravity is acting. Next to this arrow write "gravity". Then have the students draw an arrow in the direction surface tension must be acting for the water to stay in the jar. Next to this arrow write "surface tension". Finally, as a class go over the concept of surface tension. Where do they see this in their everyday life? For instance this is the same principle that tent makers use to keep water outside of the tent!