this problem refers to questions 1, 2 and 3.two students 1 and 2 are holding a long spring made of two springs a and b connected at point j (see figure). student 2 creates a pulse having a displacement only on one side of the spring (either y > 0 or y < 0). some time later (not necessarily at the same time), the students receive pulses that are on the same side of the spring (i.e. if student 1 receives a pulse with y > 0, then student 2 receives a pulse with y > 0).