An electromagnetic wave is travelling in free space.
(i) Define the terms (a) time period and (b) frequency of a wave.
(ii) Explain, without using numerical values, how the wavelength of such a wave is related to its speed and its frequency.
(iii) The electric field of the wave may be written in the form E(x,t)=E0sin(kx−ωt). State what physical quantities k and ω represent and explain how each of them is connected to a measurable spatial or temporal property of the wave.