A speaker fixed to a moving platform moves toward a wall, emitting a steady sound with a frequency of 225 Hz . A person on the platform right next to the speaker detects the sound waves reflected off the wall and those emitted by the speaker. V PartA How fast should the platform move. up, for the person to detect a beat frequency of 5.00 Hz '? Take the speed of sound to be 344 mfs. Express your answer numerically in meters per second using three signicant figures. b View Available Hintts] Ilia-00