Grade 11 General Science: Light and Sound

Vocabulary flashcards covering the key terms, physical properties, and technological applications of light and sound waves from the Grade 11 General Science transcript.

Wave

A disturbance or vibration that transfers energy from one location to another through space and matter.

Mechanical Wave

A wave that requires a material medium (such as air, water, or solids) to exist, with sound and seismic ripples as key examples.

Electromagnetic Wave

A wave composed of oscillating fields that does not require a material medium and can traverse the vacuum of space.

Wavelength

The distance between two successive identical points on a wave, measured in meters ($\text{m}$).

Frequency

The number of waves passing a specific point per second, measured in hertz ($\text{Hz}$).

Amplitude

The maximum displacement of particles from their equilibrium position, determining loudness in sound waves and brightness in light waves.

Speed of Light ($c$)

A universal constant speed in a vacuum equal to $3.0 \times 10^8\,\text{m/s}$ (or $300,000\,\text{km/s}$).

Reflection

The property of waves bouncing off surfaces, forming the basis of echoes and images.

Refraction

The bending of waves as they change speed upon entering a new medium.

Transmission

The process where light passes through an object or medium without being absorbed.

Absorption

The process occurring when light passes through a medium with the same natural frequency, causing a portion of the light energy to be absorbed.

Diffraction

The property where waves bend around obstacles and spread through openings.

Sound

A mechanical wave produced by vibrating objects that requires a medium (air, water, or solids) to travel.

Sinusoidal Sound

Sound with frequencies ranging from $20\,\text{Hz}$ to $20,000\,\text{Hz}$ that are audible to humans.

Infrasound

Sound with frequencies below $20\,\text{Hz}$, which cannot be heard by humans.

Ultrasound

Sound with frequencies above $20,000\,\text{Hz}$, which cannot be heard by humans.

Decibel ($\text{dB}$)

The unit of measurement used for sound intensity levels.

Endoscopy

A medical application that transmits light through bundles of flexible optical fibers using total internal reflection.

Phototherapy

A treatment using specific light wavelengths for healing, such as blue light to break down bilirubin in newborns or UV light for psoriasis.

Acoustic Cameras

Systems utilizing microphone arrays to pinpoint noise sources and map machinery or building problems.

Metamaterials

Engineered structures designed to bend sound waves and create quiet zones in cities.

Bone Conduction

A technology where sound vibrations bypass the eardrum entirely and transmit audio directly through the skull bone.

Light-Emitting Diodes (LEDs)

Semiconductor devices through which electric current passes to produce light efficiently with minimal heat.

Holography

A technique using laser light to record complex interference patterns and reconstruct full three-dimensional images.

LIDAR Systems

Technology emitting rapid laser pulses and measuring reflection return times to construct detailed 3D maps and detect obstacles.

Quantum Light Technology

Technology leveraging quantum entanglement for secure communication channels where any interception results in immediate detection.