Have you ever pulled out a hair just to see the way it works and how it's put together?
I have, multiple times.
Of course, there isn't much to see with the eye itself, but under a microscope, it's another story!
By pulling on each side of a hair will ultimately be an experiment in itself to test the health of the hair, but what it's interesting to see how far the hair can actually stretch before it breaks.
Strength
To demonstrate the strength of a hair, students will tape a long hair to a 12-inch ruler (or any article weighing approximately 2 ounces) and tape the other end of the hair to a rod, from which the object dangles. The hair will not break for several days. Repeat experiment with different colors ans/or types of hair to compare results.
Elasticity
To demonstrate elasticity of a hair, students will tape one end of a 4-inch hair to a key and tape the other end of the hair to the underside of a glass jar lid, letting the hair and key hang inside the jar. On the outside of the jar, mark the spot where the key hangs every day for a week. After several days, the key should descend about 1 inch.
Students will brainstorm ways they keep their hair healthy.
Assignment
- Describe the various properties of human hair.
- Describe the properties of your own hair.
- Explain how hair types occur in families.
- Describe how to care for hair to keep it healthy.
- Explain the first picture (of this post).
