Newton's laws can be applied to mechanical waves propagating in elastic media. Can they be applied to electromagnetic waves also?

The amplitude of the electric field in an electromagnetic wave is $1 \ V/m$. The frequency of the wave is $5 \times 10^{14} \ Hz$. The wave propagates along the $z$-axis. What is the average energy density of the electric field in $J/m^3$?

The velocity of an electromagnetic wave is parallel to:

$A$ lamp emits monochromatic green light uniformly in all directions. The lamp is $3\%$ efficient in converting electrical power to electromagnetic waves and consumes $100\,W$ of power. The amplitude of the electric field associated with the electromagnetic radiation at a distance of $5\,m$ from the lamp will be nearly.......$V/m$

An electric bulb is rated as $200 \, W$. What will be the peak magnetic field $(\times 10^{-8} \, T)$ at $4 \, m$ distance produced by the radiations coming from this bulb? Consider this bulb as a point source with $3.5 \%$ efficiency.

The maximum electron density of the ionosphere layer in the morning is $10^{10} \ m^{-3}$. At noon,the maximum electron density increases to $2 \times 10^{10} \ m^{-3}$. What is the ratio of the critical frequency at noon to the critical frequency in the morning?