An electromagnetic wave has a wavelength of 3.0m and a speed of 3x10^8 m/s. State what type of radiation this wave is and calculate the period of the wave.

For the first part we know that the wavelength is over 1.0 m so it is a radio wave.To find the period we first find the frequency as the period is the reciprical of the frequency. (T = 1/f).To find the frequency we use speed = wavelength x frequency and rearrange this: frequency = speed / wavelength.f = 3/(3x10^8) = 0.00000001 Hz. And then to find the time period we use T = 1/f = 1/0.00000001 = 100,000,000 seconds. This sort of wave is used to transmit radio and television programs.