Answer
$I=0.0332W/m^2$
Work Step by Step
To find the intensity of the wave, remember that the intensity of a wave is equal to the average value of the Poynting vector, which is $$I=S=\frac{1}{2\mu_o}E_mB_m$$ Using the fact that $B_m=\frac{E_m}{c}$, the intensity becomes $$I=\frac{E_m^2}{2\mu_oc}$$ Substituting known values of $E_m=5.00V/m$, $\mu_o=4\pi \times 10^{-7} H/m$, and $c=3.00\times 10^8m/s$ yields an intensity of $$I=\frac{(5.00V/m)^2}{2(4\pi \times 10^{-7}H/m)(3.00\times 10^8m/s)}=0.0332 W/m^2$$
