Physic Labs

Problem 3

Light travels from glass of refractive index 1.5 into air. Find the critical angle and condition for total internal reflection. Use the stated ideal model: quantities are constant or vary only as specified, with no extra drag, losses, or external influences. State a sign convention, keep units consistent, and use a classical approximation only where appropriate. (a) Set up the governing equation from a fundamental law. (b) Solve for the requested quantity under the stated conditions. (c) Check the result using a suitable limit, sign, or unit test, and report both the expression and its physical meaning.
sin⁡r=1.5sin⁡30∘⇒r=48.6∘\sin r=1.5\sin30^\circ\Rightarrow r=48.6^\circ
problems.proof.analysis

Substitute the intermediate result into the expression for the requested observable. Keeping parameters symbolic until this step makes dependencies clear and avoids premature rounding.