What happened to the pitch of the sound as the sound source moved past the observer? record your observations.

My GUESS is that as the sound source moved past the observer, the pitch that he heard dropped suddenly, to a lower note. That's only a guess, though. You really need to check with somebody who was there and actually observed it.

answer; (d) spontaneous processes are characterized by the overall conversion of order to disorder;

at positions a, g kinetic energy is maximum.

at position d, potential energy is maximum.