Answer:
see explanation
Explanation:
a) According to the information given, it is unclear whether if the sign of the argument of the cosine function [tex]ky \pm (1.2501013rad/s )t[/tex]. However I am going to solve it for both signs, if there is a minus sign then it is traveling in +y direction, if there is a plus sign then it is traveling in -y.
b) now for the wavelength we have the following:
[tex]\omega = 2\pi f = 1.2501013=>f =0.19896 [Hz][/tex]
[tex]\lambda = \frac{c}{f} = \frac{3*10^8}{0.19896} = 1.5*10^9 [m][/tex]
