Total energy when positions vs time graph is given 1. The problem statement, all variables and given/known data (answer: -5J) 2. Relevant equations energy initial = energy final 3. The attempt at a solution At the crest of each wave, the particle has only potential energy, and at the middle of each wave the particle has only kinetic energy, and these values are equal. By looking at the slope when the graph crosses the horizontal axis, you can determine that it travels at 5m/s then. After this point, I do not know how to continue.