Question

Students 1 and 2 each generate a single transverse pulse by moving the ends of a spring. Originally, there was a line of cups along one side of the spring as shown. Assume each pulse was generated only on the bottom of the spring (toward the cups). Top view (before any pulses have been created) Student 1 Student 2 оооо O O Only two of the cups were disturbed, as shown below. Did Student 1 begin generating their pulse before, after, or at the same time as Student 2? Assume the pulses have the same shape and width. Top view Student 1 disturbed cups Student 2 O ooo Student 1 generated their pulse at the same time as Student 2 There is not enough information to answer. Student 1 generated their pulse after Student 2 Student 1 generated their pulse before Student 2

The correct answer is the last one: Student 1 generated their pulse before Student 2. Why is this the case?

Answer 1

Student 1 generated the pulse before student 2 because the velocity of the pulses generated is the same but generated time is different. If both generated at the same time the pulses might superpose in the middle of the string. Or if student 1 generated the pulse after student 2 the superposition of pulse might take place near to the student 1. Since because student 1 generated the pulse after student 2 the superposition took place near student 2.