the acceleration a(t) of a particle undergoing shm is graphed in fig. 15-21. (a) which of the labeled points corresponds to the particle at !xm? (b) at point 4, is the velocity of the particle positive, negative, or zero? (c) at point 5, is the particle at !xm, at %xm, at 0, between !xm and 0, or between 0 and %xm?
