Physical Science Unit 4 (Waves) Terms: Spring 26'

Wave

A disturbance that transfers energy from one location to another without transferring matter

Mechanical Wave

A disturbance that transfers energy through a physical medium by causing particles to vibrate or oscillate

Longitudinal Wave

A type of wave where the particles of the medium vibrate parallel to the direction of energy transfer

Transverse Wave

Wave that moves the medium in a direction perpendicular to the direction in which the wave travels

Electromagnetic Wave

A wave that consists of oscillating electric and magnetic fields, which radiate outward at the speed of light

Amplitude

The maximum displacement on either side of equilibrium

Wavelength

A measurement of the distance between two repeating points (trough/crest) of a wave

Frequency

The number of waves that pass each second. Measured in herts (Hz)

Compressions

A region in a longitudinal wave where the particles of the medium are pushed closest together

Rarefactions

A segment in a longitudinal wave where particles are spread apart

Standing Wave

A wave that appears stationary, with fixed points of minimum (node) and maximum (antinode) displacement

Interference

When two or more waves overlap to form a resultant wave of higher, lower, or equal amplitude

Law of Reflection

Angle of incidence equals angle of reflection

Rarefaction

A process in which the speed of light increases (less dense) or decreases (denser) due to the medium

Real Image

An upside-down image formed where rays of light meet

Virtual Image

An image that forms at a location from which light rays appear to come but don't actually come

Diffraction

Occurs when an object causes a wave to change direction and bend around it

Doppler Effect

An observed change in the frequency of a wave when the source or observer is moving

Resonance

When two objects naturally vibrate at the same frequency

Coherent Light

(Light) waves that maintain a fixed, predictable phase relationship with each other, meaning their crests/troughs are synced

Total Internal Reflection

The complete reflection of light by the inside surface of a medium

Photoelectric Effect

The emission of electrons from a metallic surface when light shines on metal

Concave Mirror

A mirror with a surface that curves inward (like a bowl)

Convex Mirror

A mirror with a surface that curves outward (like a spoon)

Concave Lens

A lens that is thicker at the edges than in the middle that bends light rays away from one another

Convex Lens

A lens that is thicker in the middle than the edges

Converging

When two or more wave systems, or parts of a single wave, come together and meet at a single point or along a line

Diverging

Waves that spread out as they travel away from a source or pass through a narrow aperture

Red, Green, Blue

What Are the Primary Colors of Light?

Cyan, Yellow, Magenta

What Are the Secondary Colors of Light?

300,000,000 m/s

What is the Speed of Light?

343 m/s

What is the Speed of Sound?

V=λf

Velocity equals wavelength (m) multiplied by frequency (Hz)

What is the Wave Speed Equation?

Medium

The substance or material (solid, liquid, gas, or plasma) that carries a mechanical wave from one location to another

Ray Tracing Rules for Converging (Convex) Lenses:

1) A ray entering a converging lens parallel to its axis passes through the focal point (F) of the lens on the other side

2) A ray passing through a center of either a converging or a diverging lens does not change direction

3) A ray entering a converging lens through its focal point exits parallel to its axis

Ray Tracing Rules for Diverging (Concave) Lenses:

1) A ray entering a diverging lens parallel to its axis seems to come from the focal point (F)

2) A ray passing through the center of either a converging or diverging lens does not change direction

3) A ray enters a diverging lens by heading toward the focal point on the opposite die exits parallel to the axis