Boundary Behavior of Waves and Polarization - AP Physics 2

Wave reflection is when a wave bounces back after hitting a boundary. Energy cannot pass through the boundary, so it returns to the original medium.

The change in wave speed affects refraction. Speed changes cause direction changes at boundaries.

$\tan(\theta_B) = \frac{n_2}{n_1}$. Derived from the condition that reflected and refracted rays are perpendicular.

Reflection occurs when wave impedance changes. Impedance mismatch causes partial reflection at interfaces.

The amplitude decreases. Wave peaks and troughs align to cancel displacement.

Wave speed decreases with increased medium density. Inverse relationship between medium density and wave speed.

A medium with uniform properties in all directions. Wave properties are identical in all spatial directions.

Wave's electric field rotates in a circle around the direction of travel. Electric field vector traces circular path perpendicular to propagation.

Polarization reduces the light intensity. Filtering light waves removes some energy from the beam.

The angle where reflected light is completely polarized. Occurs when the reflected ray is perpendicular to the refracted ray.

The change in wave speed affects refraction. Speed changes cause direction changes at boundaries.

The total displacement is the sum of individual displacements. Multiple waves combine by adding their displacements at each point.

Amplitude generally decreases in a denser medium. Denser media typically absorb more energy from waves.

To reduce glare and enhance contrast. Removes unwanted reflections and improves image clarity.

Interference results in either increased or decreased wave amplitude. Depends on phase relationship between overlapping waves.

Phase difference is $0$ or multiples of $2\text{π}$. Waves are in phase, creating maximum reinforcement.

$\theta_c = \text{sin}^{-1}(\frac{n_2}{n_1})$. Critical angle depends on the ratio of refractive indices.

Intensity is reduced by half. Unpolarized light becomes 50% intensity after polarization.

Reflected light is completely polarized. At this specific angle, reflected light has maximum polarization.

Transmission is when a wave passes through a boundary into a new medium. Part of wave energy continues into the second medium.

Polarization reduces glare. Eliminates horizontally polarized reflected light from surfaces.

Occurs when the aperture size is comparable to the wavelength. Significant bending occurs when $\lambda \approx$ aperture size.

Diffraction is the bending of waves around obstacles. Wave spreading occurs when encountering edges or apertures.

$n_1 \times \text{sin}(\theta_1) = n_2 \times \text{sin}(\theta_2)$. Relates incident and refracted angles through refractive indices.

Refraction is the change in wave direction at a boundary. Speed changes cause waves to bend when entering new media.

Occurs when the angle of incidence exceeds the critical angle. When $\theta_i > \theta_c$, all energy reflects and none transmits.

Angle of incidence equals angle of reflection. This is a fundamental principle governing all types of wave reflection.

Wave reflection is when a wave bounces back after hitting a boundary. Energy cannot pass through the boundary, so it returns to the original medium.

The wave's speed decreases. Denser media have higher refractive indices, slowing wave propagation.