The wavelength of an electromagnetic wave is given by
[tex]\lambda = \frac{c}{f} [/tex]
where [tex]c=3 \cdot 10^8 m/s[/tex] is the speed of light and [tex]f=1.10 kHz = 1100 Hz[/tex] is the frequency. Substituting the numbers, we find
[tex]\lambda = \frac{3 \cdot 10^8 m/s}{1100 Hz}=2.72 \cdot 10^5 m=272 km [/tex]
So, the wave in the problem has a wavelength of 272 km.
