* Physical Change: A physical change alters the form or appearance of a substance, but it does not change the substance's chemical composition.
* Haircut: Cutting hair only changes the length and shape of the hair strands. The hair is still hair; its chemical makeup hasn't been altered. It's simply been rearranged.
Contrast this with a chemical change, where a new substance is formed. For example, burning wood is a chemical change because it produces ash, smoke, and gases, which are different substances than the original wood.