phys: fix intensity formula

2021-01-11 16:08:55 -05:00 · 2021-01-11 16:08:55 -05:00 · 49dc3d1fb7
commit 49dc3d1fb7
parent 037e7256a7
1 changed files with 1 additions and 1 deletions
--- a/docs/sph3u7.md
+++ b/docs/sph3u7.md
@ -699,7 +699,7 @@ $$E\propto I\propto A^2$$
 $$E=E_0\cos\theta$$

 And so:
-$$I=I_0\cos\theta$$
+$$I=I_0\cos^2\theta$$

 When **unpolarised light** passes through a polariser, the average result of $I\cos\theta$ is $\frac{1}{2}$, so the intensity of polarised light is **half** of the intensity of unpolarised light.