A normal human heart, beating about once per second, creates a maximum 4.00 mV potential across 0.400 m of a person's chest, producing a 1.00 Hz electromagnetic wave. What is the maximum electric field strength produced

Aflute player hears four beats per second when she compares her note to a 523 hz tuning fork (the note c). she can match the frequency of the tuning fork by pulling out the “tuning join” to lengthen her flute slightly. what was her initial frequency?