Solution:
Solution
Electric field of an EM wave $$\vec{E} =30 (kz - 5\times 10^8 t) \hat{i}$$
$$\implies$$ $$\omega = 5\times 10^8$$ rad/s
Given : Velocity of EM wave $$v = 3\times 10^8$$ $$m/s$$
Using $$v = \dfrac{w}{k}$$ $$\implies k = \dfrac{w}{v}$$
$$\therefore$$ $$k = \dfrac{5\times 10^8}{3\times 10^8} = 1.66$$ rad $$m^{-1}$$