Three long, flexible strings—A, B, and C—are joined end-to-end so that waves may travel from one into the next without additional external forces. All three segments are under the same tension. Measurements give the following wave speeds:
• String A: 15 m/s
• String B: 9 m/s
• String C: 18 m/s
A narrow, upward-oriented transverse pulse is generated in String A far from the first junction and travels toward the A–B boundary.
(a) State whether the pulse reflected at the A–B boundary is inverted or upright. Support your answer with appropriate reasoning.
(b) The portion of the pulse transmitted into String B eventually reaches the B–C boundary. Determine the orientation (inverted or upright) of the pulse reflected at this second boundary back into String B and justify your choice.
(c) The pulse described in part (b) now travels leftward through String B, returning to the A–B junction. When that pulse reflects back into String A, is its orientation inverted or upright relative to the pulse described in part (a)? Explain carefully.
(d) After all three reflections described above, the original observer in String A sees a pulse returning toward the point of origin. Specify the final orientation (upright or inverted) of that returning pulse relative to the initial pulse and summarize the sequence of inversions that led to your conclusion.