The electric field in a plane electromagnetic wave is given by
$$\vec{E} = 200 \cos[(0.5 \times 10^3 \text{ m}^{-1})x - (1.5 \times 10^{11} \text{ rad s}^{-1})t] \text{ V m}^{-1} \hat{j}$$.
If this wave falls normally on a perfectly reflecting surface having an area of 100 cm$$^2$$. If the radiation pressure exerted by the E.M. wave on the surface during a 10 min exposure is $$\frac{k}{10^9}$$ N m$$^{-2}$$. Find the value of $$k$$