Physics
Physics
Problem
When a transverse pulse traveling along a light string reaches a junction with a much heavier string, the tension remains the same in both strings. Which statement describes the orientation of the reflected pulse on the light string? a) It maintains the same orientation as the incident pulse. b) It is inverted relative to the incident pulse. c) It vanishes because all energy is transmitted into the heavier string. d) It is shifted by in phase relative to the incident pulse.Intuitive explanation
When a wave hits a boundary where the medium changes, the key is to think about what happens at that junction point. Since the heavy string is much harder to move, it acts almost like a fixed wall—the junction can barely budge upward. A pulse reflecting off a nearly fixed boundary flips its orientation (inverts), while one reflecting off a free end stays upright. Here, the heavy string's resistance to motion creates a reflection similar to a fixed end, so the reflected pulse will be inverted relative to the incident pulse.
Intuitive explanation
When a wave hits a boundary where the medium changes, the key is to think about what happens at that junction point. Since the heavy string is much harder to move, it acts almost like a fixed wall—the junction can barely budge upward. A pulse reflecting off a nearly fixed boundary flips its orientation (inverts), while one reflecting off a free end stays upright. Here, the heavy string's resistance to motion creates a reflection similar to a fixed end, so the reflected pulse will be inverted relative to the incident pulse.