Awireless transmitting microphone is mounted on a small platform that can roll down an incline, directly away from a loudspeaker that is mounted at the top of the incline. The loudspeaker broadcasts a tone that has a frequency of 1.000 X 104 Hz, and the speed of sound is 343 m/s. At a time of 1.5 5 following the release of the platform, the microphone detects a frequency of 9864 Hz. At a time of 3.5 5 following the release of the platform, the microphone detects a frequency of 9684 Hz. What is the acceleration a (assumed constant) of the platform? a=n