Your friend wants to test your understanding of waves. She weaves together one end of two different ropes (one with greater mass density than the other, but each with the same radius and length) to make a single rope. Then she attaches one end of the combination to a pole. You are blindfolded and asked to hold the other end of the stretched rope. Your friend expects you to determine not only which end you are holding (the heavier or lighter rope), but also whether your friend used a fixed or free method of attachment to the pole. You think for a minute, then laugh and declare that you can even estimate the ratio of the linear mass densities! While she is speechless, you create a single wave pulse with your hand.