Glossary and Terms for Physics
Absorption – Absorption is when some of the wave’s energy is taken away when a wave encounters a medium.
Amplitude – The measure of the displacement of the wave from its rest position. The higher the amplitude of a wave, the higher is its energy.
Coherence – Two waves are said to be coherent when they have a constant phase difference between them.
Crest – The crest is the highest point of a wave. The opposite of the crest is the trough.
Diffraction – Diffraction is when a wave remains in the same medium, but bends around an obstacle.
Electromagnetic Waves – Electromagnetic waves are waves that can travel through a vacuum. They do not need a medium. Light is a type of electromagnetic wave.
Frequency – The frequency of a wave is the number of times per second that a wave cycles. The frequency is the inverse of the period.
Intensity – A measurement of the strength of a sound wave that is equal to the power divided by the area.
Interference – Interference is when one wave comes into contact with another wave.
Light-wave – A light wave is a special type of electromagnetic wave that has a frequency in the visible spectrum.
Longitudinal – A longitudinal wave is a wave where the disturbance travels in the same direction as the wave. Sound waves are longitudinal.
Mechanical Waves – A mechanical wave is a wave that must travel through some sort of matter called a
medium. Mechanical waves cannot travel through a vacuum like outer space.
Medium – The medium is the matter that a wave travels through.
Period – The period of a wave is the time between wave crests. It is the inverse of the frequency.
Polarization – Polarization is when a wave oscillates in one particular direction. Light waves are sometimes polarized by a special polarizing filter.
Reflection – Reflection occurs when a wave bounces off a boundary, changing direction but remaining in the same medium.
Read More: Law of reflection of light
Refraction – The change in direction and wavelength when a wave moves from one medium to another.
Read More: Laws of refraction of light
Refractive Index – A refractive index is a number that describes how light travels through a specific medium. Different mediums have different refractive indexes. The refractive index of a vacuum is defined to be 1.
Resonance – Resonance is the tendency for a system to oscillate with greater amplitude at some frequencies than at others.
Resting position – The resting position is the position the medium would take if there were no wave. It is represented on a graph by a line through the centre of the wave.
Sound wave – Sound waves are mechanical waves that are caused by vibration. Sound waves can be heard by our ears.
Speed – The speed of a wave is a measure of how fast the disturbance of the wave is moving. The speed can be dependent on the type of medium that a wave is moving through.
Standing wave – A standing wave is a wave that remains in a constant position.
Transverse – A transverse wave is a wave where the disturbance moves perpendicular to the direction of the wave.
Wave – A wave is a travelling disturbance that moves through space and matter. Waves transfer energy from one place to another, but not matter.
Wavelength – The wavelength of a wave is the distance between two corresponding points on back-to-back cycles of a wave. For example, between two crests of a wave.
Trough – The trough is the lowest part of the wave. The opposite of the trough is the crest.