Suppose that intensity of a laser is ((315)/(π))W m ^ - 2 . The rms...

$\dfrac{1}{2}C{\in}_{0}{E}_{ms}^{2} = \dfrac{315}{\pi}$

${E}_{rms} = \sqrt{\dfrac{315 \times 2}{\pi \times 3 \times {10}^{8} \times 8 . 86 \times {10}^{- 12}}}$

$= \sqrt{\dfrac{630}{83 . 4612 \times {10}^{- 4}}}$

$= \sqrt{7 . 5484 \times {10}^{4}}$

$= 2 . 75 \times {10}^{2} = 2 . 75 \times {10}^{2} = 275$