## University Physics with Modern Physics (14th Edition)

$23.7W/cm^2$.
Let the incident intensity be $I_0$.With all three polarizers, the transmitted intensity is: $$I= \frac{1}{2}I_o cos^2 23.0^{\circ} cos^2 (62.0^{\circ}-23.0^{\circ})=0.2559I_0$$ $$55.0W/cm^2=0.2559I_0$$ $$I_0=215W/cm^2$$ After removing the second polarizer, with only the first and third polarizers in place: $$I= \frac{1}{2}I_o cos^2 62.0^{\circ}=0.110I_0=0.110(215W/cm^2)= 23.7W/cm^2$$