Answer: [tex]2.9(10)^{-4} Hz[/tex]
The frequency is defined as the inverse of the period [tex]T[/tex] (time):
[tex]f=\frac{1}{T}[/tex] (1)
And according to the International Units System its unit is Hertz ([tex]Hz=1/s[/tex]).
This means we have to convert this quantity given in minutes to seconds before solving the equation:
[tex]T=56.8 min.\frac{60s}{1min}=3408s[/tex] (2)
Substituting (2)in (1):
[tex]f=\frac{1}{3408s}[/tex]
Finally:
[tex]f=0.00029Hz=2.9(10)^{-4} Hz[/tex]
