Respuesta :

Answer:

F = 9.675Hz

Explanation:

pls for certain reasons let us make

  • wavelength = $
  • frequency = F
  • V = velocity

3 loops : 6$/4 = L

6$/4 = 2

$ = 4/3 = 1.333

V = F x $

F = V/$

F = 12.9/1.333 = 9.675Hz

F = 9.675Hz