3. The electric field of an electromagnetic wave in a vacuum is \mathbf{E}=120.0 \mathrm{~V} / \mathrm{m} \cos \left[-\left(316.28 \times 10^{5}\right) \times-2 \pi \mathrm{ft}\right\rceil where x is in m and t is in s. [ 12 points ] a. What are the wavelength of the wave? [ b. What type of light is this? c. What is the frequency of the wave? d. What is the magnitude of the wave's magnetic field? e. The wave is moving in the negative-x direction (why there are negative values in the cosine). At position x=0 and time t=0, the electric field is aligned along the +z direction. What is the direction of the magnetic field? [1 pt]