The electric field in a plane electromagnetic wave is given by

The electric field in a plane electromagnetic wave is given by

$\overrightarrow{\mathrm{E}}=200 \cos \left[\left(\frac{0.5 \times 10^{3}}{\mathrm{~m}}\right) \mathrm{x}-\left(1.5 \times 10^{11} \frac{\mathrm{rad}}{\mathrm{s}} \times \mathrm{t}\right)\right] \frac{\mathrm{V}}{\mathrm{m}} \hat{\mathrm{j}}$

If this wave falls normally on a perfectly reflecting surface having an area of $100 \mathrm{~cm}^{2}$. If the radiation pressure exerted by the E.M. wave on the surface

during a 10 minute exposure is $\frac{\mathrm{x}}{10^{9}} \frac{\mathrm{N}}{\mathrm{m}^{2}}$. Find the value of $x$.