Topic 5 - Waves & Electromagnetic Radiation (Vocabulary Only)

Wave

A disturbance that transfers energy from place to place

Mechanical Wave

A wave that requires a medium through which to travel

Medium

Material through which a wave travels

Electromagnetic Radiation

The energy transferred through space by electromagnetic waves.

Transverse Wave

a wave that causes the medium to vibrate at right angles to the direction in which the wave travels

Amplitude

the maximum distance the particles of a medium move away from their rest positions as a longitudinal wave passes through the medium

Longitudinal Wave

A wave that moves the medium in a direction parallel to the direction in which the wave travels.

Wavelength

The distance between two corresponding parts of a wave

Frequency

the number of complete wavelengths that pass a point in a given time

Reflection

The bouncing back of a wave when it hits a surface through which it cannot pass.

Refraction

the bending of a wave as it enters a new medium at an angle

Diffraction

The bending of a wave as it moves around an obstacle or passes through a narrow opening

Absorption

the transfer of energy from a wave to a material that it encounters

Intereference

the interaction between waves that meet

Standing Wave

a wave that appears to stand in one place, even though it is really two waves interfering as they pass through each other

Resonance

The increase in the amplitude of a vibration that occurs when external vibrations match an object's natural frequency.

Loudness

the perception of the energy of a sound.

Intensity

the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave's amplitude

Decibel

a unit that compares the intensities of different sounds

Pitch

the highness or lowness of a sound

Doppler Effect

The change in frequency of a wave as its source moves in relation to an observer

Electromagnetic Wave

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

Electromagenetic Spectrum

the complete range of electromagnetic waves placed in order of increasing frequency

Radio Waves

Electromagnetic waves with the longest wavelengths and lowest frequencies

Microwaves

Electromagnetic waves that have shorter wavelengths and higher frequencies than radio waves.

Visible Light

Electromagnetic radiation that can be seen with the unaided eye

Ultraviolet Rays

Electromagnetic waves with wavelengths shorter than visible light, but longer than x-rays

Infrared Rays

Electromagnetic waves with shorter wavelengths and higher frequencies than microwaves.

X-Rays

electromagnetic waves with wavelengths shorter than ultraviolet rays, but longer than gamma rays

Gamma Rays

Electromagnetic waves with the shortest wavelengths and highest frequencies

Transparent

A material that allows light to pass through without scattering light.

Translucent

Allowing light to pass through

Opaque

A type of material that reflects or absorbs all of the light that strikes it.

Diffuse Reflection

Reflection that occurs when parallel rays of light hit a rough surface and all reflect at different angles

Convex

A mirror with a surface that curves outward or lens that is thicker in the center than at the edges.

Focal Point

the point at which rays parallel to the optical axis reflect and meet

Concave

a mirror with a surface that curves inward or a lens that is thinner at the center than the edges.