A plane monochromatic electromagnetic wave with wavelength λ=2.0cm, propagates through a vacuum. Its magnetic field is described by >B⃗ =(Bxi^+Byj^)cos(kz+ωt), where Bx=1.9×10−6T, By=4.7×10−6T, and i^ and j^ are the unit vectors in the +x and +y directions, respectively. What is Sz, the z-component of the Poynting vector at (x=0,y=0,z=0) at t=0?