Answer:
[tex]dF=2.5Hz[/tex]
Explanation:
From the question we are told that:
Time [tex]T=0.2sec[/tex]
Generally the Period is given as
[tex]T= 2 * 0.2 = 0.4[/tex]
Therefore difference in frequency dF
[tex]dF=\frac{1}{T}[/tex]
[tex]dF=\frac{1}{0.4}[/tex]
[tex]dF=2.5Hz[/tex]