A speaker fixed to a moving platform moves toward a wall, emitting a steady sound with a frequency of 230 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.

How fast should the platform move, vp , for the person to detect a beat frequency of 5.00 Hz ?

Take the speed of sound to be 344 m/s .

Express your answer numerically in meters per second using three significant figures.