Section Ten Waves Vocabulary

Vocabulary flashcards defining key terms and concepts related to refraction, reflection, light waves, water waves, and general wave behavior.

Refraction

The bending of light when it travels from one transparent medium to another.

Medium

Any substance that light or sound travels through.

Opaque Material

A substance that light cannot pass through (not see-through).

Transparent Material

A see-through material that light will travel through.

Refraction from Less Dense to More Dense Medium

The bending of light towards the normal when entering a more dense medium (such as light travelling from air to glass).

Refraction from More Dense to Less Dense Medium

The bending of light away from the normal when entering a less dense medium (such as light travelling from glass to air).

Unrefracted Light Ray

A light ray that hits a medium straight on at an angle of $90^\times$ (perpendicular) and does not bend.

Normal

An imaginary line drawn at a right angle ($90^\times$) to a surface.

Specular Reflection

Reflection where each light ray reflects off a smooth, shiny surface at the same angle, producing a clear reflection.

Diffuse Scattering

Reflection off a rough, dull surface where light is reflected back in lots of different directions.

Law of Reflection

The rule stating that the angle of incidence equals the angle of reflection ($\text{Angle of Incidence} = \text{Angle of Reflection}$).

Angle of Incidence

The angle at which a light ray hits a surface, measured between the light ray and the normal.

Angle of Reflection

The angle at which a light ray leaves a surface, measured between the light ray and the normal.

Luminous Objects

Objects that produce light, such as the Sun, light bulbs, and flames.

Vacuum

A space containing nothing at all — no air, no particles, and no matter.

Speed of Light in a Vacuum

The speed at which light travels when in a vacuum, which is equal to $300\,000\,000\text{ m/s}$.

Crest

The highest part of a wave.

Trough

The lowest part of a wave.

Wave Cancellation

The event occurring when an identical crest and trough meet and briefly cancel each other out.

Transverse Wave

A wave with undulations (up and down movements) that occur at right angles ($90^\times$) to the direction the wave is travelling in.

Undulations

The up and down movements of a wave that occur at right angles to the direction of wave movement.