A radio wave travels through space with a frequency of 2 x 104 Hz. If the speed of the radio wave is 3 x 108 m/s,
what is the wavelength of this wave?
O 6 x 10^12 m
O 1 x 10^4 m
O 6.7 x 10^-4 m
O 1.5 x 10^4 m