WAV-21

Malus law

Polarizer intensity.

Reading speed

GoverningMalus law

Governing equation

I=I_0\cos^2\theta

where

I0: I0 (W/m²)
th: th (deg)
I: Malus law (W/m²)

Lecture brief

Historical brief

d’Alembert’s wave equation, Snell, the thin-lens maker, Doppler and Bragg interference are the classical optics-and-sound toolkit. The lab is propagation, image and shift. This sheet (WAV-21 — Malus law) is the form associated with Malus law. Working symbols: $I0$ , $th$ $\rightarrow$ $I$ . Polarizer intensity. Pedagogical SI sheet with a live model and a swept parameter.

Purpose

Purpose: compute

I

from

I0

th

in Waves & optics via

I=I_0\cos^2\theta

Polarizer intensity. Use it when a real waves & optics question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given

I0 = 1.000\,\mathrm{W/m^{2}}

th = 30.000\,\mathrm{deg}

, the governing relation

I=I_0\cos^2\theta

yields

I = 0.750\,\mathrm{W/m^{2}}

. One governing identity, SI units, a single sweep on the sheet. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

I0 I01 W/m²th th30 deg

Outputs

Malus law I0.750 W/m²

Reading speed

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Narration of this film

One governing identity, SI units, a single sweep on the sheet.

Polarizer intensity. Pedagogical SI sheet with a live model and a swept parameter.

Reading speed

Watch on YouTube