Glossary
Energy and its Transformation
Absorption
This is the process of retaining radiation without reflecting it.
Amplitude
In a transverse wave, this is the magnitude of height of a wave from origin to crest.
In a longitudinal wave, this is corresponds to how much the wave is compressed, as compared to areas of
little compression.
Angle Of Incidence
This is the angle that light strikes a surface relative to the normal, or an imaginary line perpendicular to the
surface. The law of reflection states that this angle is equal to the angle of reflection.
Angle Of Reflection
This is the angle at which light leaves or bounces off of a surface relative to the normal, or an imaginary
line perpendicular to the surface. The law of reflection states that this angle is equal to the angle of
incidence.
Black
This is the color of objects that do not reflect light from any part of the visible spectrum; they absorb all
frequencies of visible light.
Chemical Energy
Energy stored in chemical bonds of molecules.
Color
This is a physical property of all visible light determined by the light's frequency and visible to the human
eye.
Compression
This is the increase in density of a medium due to wave travel.
Compression Wave
Also called a longitudinal wave, they are waves whose direction of vibration is the same as their direction of
travel. They produce compression and rarefaction when traveling through a medium.
Conduction
This is heat or electrical transfer by contact.
Conductor
This is a material that allows heat/electricity to transfer.
Conservation Of Energy
This law states that, in any process, energy is neither created nor destroyed. It can only be converted from
one form to another.
Convection
This is heat transfer due to differences in density.
Crest
This is the peak, or highest point, of a wave.
Decibel
This is a measure of sound pressure level.
Density
This is a measure of mass per unit volume.
Diffraction
This is a spreading out of a wave around corners or through holes.
Doppler Effect
A change in sound frequency due to the relative motion of either the source of sound or the detector.
Earthquake
This is a geologic event that occurs when tectonic plates are displaced violently.
Echolocation
This is a method used by some animals, bats for example, that uses sound waves to help locate prey and
other objects in the dark.
Elastic Potential Energy
This is energy stored in a deformed object.
Electrical Energy
Energy created by the flow of electrons through a conductor.
Electricity
This is a flow of electrons that creates a charge, one of the fundamental forms of energy.
Electromagnetic Spectrum
The complete range of light waves organized by wavelength/frequency.
Electromagnetic Wave
A propagating wave in space with electric and magnetic components. These components oscillate at right
angles to each other. It may travel in a vacuum.
Energy
The capacity for doing work. It may be transformed from one form to another.
Energy Transformation
This is the process of changing energy from one form to another. Solar energy is changed into chemical
energy by plants.
Frequency
This is the number of complete movements of a wave per second.
Gravitational Potential Energy
This is the energy an object possesses because of its position in a gravitational field. It is dependent of
mass and height.
Gravity
This is an attractive force between any two objects due to mass.
Heat
The transfer of thermal energy between two bodies which are at different temperatures. The SI unit for this
is the Joule. Generally considered the raising of temperature due to thermal energy.
Heat Energy
This is the form of energy that is transferred because of a difference in temperature.
Incident Ray
This is a ray of light that strikes a surface.
Joule
This is the SI (metric) unit of energy or work.
Kinetic Energy
This is energy of motion.
Light Energy
Energy in the form of electromagnetic radiation. Most often associated with a wavelength that is visible to
the eye.
Light Energy
This is the type of energy that radiates through space; allows us see, especially colors,
Liquid
This is the phase of matter with no fixed shape but fixed volume.
Longitudinal Wave
This is wave whose energy travels in the same direction as the energy is transferred.
Mass
This is a measure of the quantity of matter.
Mechanical Energy
The energy transferred by a force to a moving object.
Mechanical Wave
A wave which needs a medium (solid, liquid, gas) in order to propagate itself.
Medium
This is the material in which a mechanical wave travels.
Metals
This is a group of elements with few valence electrons that conducts heat and electricity.
Motion
This is a change in the position of a body with respect to time relative to a reference point.
Ocean Wave
These usually result from wind and can travel hundreds of miles before they reach the shore.
Opaque
This is any material that allows no light waves to be transmitted through. Light waves are either absorbed
or reflected.
Period
This is the time for one complete wave oscillation.
Pitch
This is the high or low tone or frequency in which a speech is made.
Plane Mirror
This is a flat mirror that produces an image is always the same distance behind the mirror as the object is
in front of the mirror.
Position
This is the location of an object.
Potential Energy
Energy that is stored.
Prism
This is transparent optical element with flat, polished surfaces that refracts light.
Radiation
Heat transfer by electromagnetic waves.
Rarefaction
This is the reduction in the density of a medium.
Reflected Ray
This is a ray that represents the light reflected by the surface.
Reflection
The bouncing back of a wave from a surface.
Refraction
The bending of a wave as it moves from one medium to another.
Seismic Wave
This is a wave that travels through the Earth or other elastic body, as the result of an earthquake,
explosion, or some other process that exerts a force on the body.
Solar Energy
This is the utilization of radiation from the sun.
Solid
This is the phase of matter with fixed shape and volume.
Sonar
This is a technique that uses the bounce back, or echo, of a sound wave to determine the location and/or
direction of another object.
Sound
A compression wave of gas, liquid, or solid, that is detected by your ear.
Sound Energy
This is the energy created by a compression wave of gas, liquid, or solid, that is detected by your ear.
Sound Intensity
This is the sound power per unit area and is measured in decibels.
Sound Volume
This is the loudness or softness of a sound.
Speed
This is the rate of distance traveled per unit of time, without regard to direction.
Speed Of Light
This is the speed of 186,000 miles/second or 300,000 kilometers/second and is used to determine
distances in space.
Spring Scale
Equipment used to measure force.
Temperature
This is a measure of the average kinetic energy of a substance.
Thermal Energy
Random kinetic energy possessed by objects in a material at finite temperature. An object that feels hot
has a lot of this.
Transformation
Process of changing from one form of energy to another.
Translucent
This is any material that transmits some light, but causes the light to be scattered so no clear image is
seen.
Transparent
This is any material that that transmits most of the light that strikes to pass through and only a small
amount of light is reflected or absorbed.
Transverse Wave
This is a type of wave that travels in one direction, but the energy travels perpendicular to this direction.
Trough
This the bottom, or lowest point, of a wave.
Vacuum
This is a volume of space that is empty of matter.
Velocity
This is an object's change in motion per unit time in a specified direction.
Visible Light
This is the portion of the electromagnetic spectrum that human eyes can detect.
Wave
A rhythmic disturbance that carries energy through matter or space.
Wavelength
This is the distance from the peak to a peak of a successive wave.
Weight
This is the force of attraction between an object and the earth due to gravity.
Wind Energy
This is energy from moving air.