복사압은 완전 흡수 조건에서

\displaystyle P_{\mathrm{rad}} = \dfrac{P_{\mathrm{power}}}{A c}

입니다.

\displaystyle P_{\mathrm{rad}} = \dfrac{50.0 \times 10^{-3}\ \mathrm{W}}{(\pi (0.0020\ \mathrm{m})^2)(3.00 \times 10^8\ \mathrm{m/s})} \approx 1.3 \times 10^{-5}\ \mathrm{Pa}