Asinusoid al em wave of frequency 80 mhz travels in free space in the x- direction. (a) find the period and wavelength of the wave. (b) at some instant and location, the e field has its maximum value of 650 n/c and is directed along the y-axis. find the magnitude and direction of the magnetic field b at this position and time. (c) write an expression for b in unit vector notation using a cos function, with w. numericat values for bmax, k, and