This can also demonstrate reflection (1) and refraction (2) if

• (1) Tied to a solid object the traveling wave will reflect and travel back.
• (2) If a rope with a different density/unit length is tied to the end of the green rope and the new rope tied to a solid object.

• Either hold this rope from both ends (needing a second person) or fix one end to a solid object and make a whipping type motion.