1. The problem statement, all variables and given/known data 6 Earthquakes produce transverse and longitudinal seismic waves that travel through rock. Figure 8 shows the displacement of the particles of rock at a given instant, for different positions along a transverse wave. Figure 8: (b) Describe the motion of the rock particle at point B during the passage of the next complete cycle. (2 marks) 2. Relevant equations 3. The attempt at a solution So I thought that point B of the next cycle is the point at equilibrium after point C. So then I figured that the particle would move down (from point B or equilibrium) to maximum negative displacement, and then up to equilibrium. And that would be the end of the cycle (which starts at point C?). The answer however is this: (oscillates from equilibrium to maximum positive displacement, back to equilibrium, then to max negative displacement) and back to equilibrium /starting position /rest position. So, I guess one difference is that they explained the motion during the whole cycle, but why? Aren't they asking for point B?