Standing wave motion in strings Steps: - In a standing wave, the solid curve at time t shows maximum upward displacement, with antinodes at peaks and nodes at zero crossings. - The dashed curve represents the next maximum, downward displacement, indicating oscillation direction reversal at antinodes. - Points P and Q are on the mean position line, likely near antinodes or on opposite sides of a node, so their initial motion after t follows the wave's transverse velocity. - Shortly after maximum displacement, all points move toward equilibrium, with directions determined by proximity to nodes: opposite sides move oppositely. Why B is correct: - In standing waves, points on opposite sides of a node (like P and Q) experience 180° phase difference, displacing in opposite directions per the wave equation y(x,t) = 2A sin(kx) cos(ωt). Why the others are wrong: - A: Point R, likely a node, remains undisplaced as nodes have zero amplitude. - C: Points equidistant from a node (R) vibrate 180° out of phase, not in phase. - D: Points S and T, at similar positions relative …