Acceleration
The rate of change of velocity
Accurate result
A result that is close to the true answer
Apha decay
A type of decay in which
... [Show More] an unstable nucleus of an atom emits an alpha particle
Alternating current
A current that changes with time in a regular cycle
Ammeter
A component used to measure the current flowing through a circuit
Amplitude
The maximum displacement of a wave
Angle of incidence
The angle that incoming light makes to the normal or a boundry
Angle of refraction
The angle that incoming light makes to the normal of a boundary
Annihilation
The process by which a particle and its antiparticle meet and their mass gets converted to energy in the form of a pair of gamma ray photons
Anomalous result
A result that doesn't fit in with the pattern of the other results in a set of data
Antimatter
The name given to all antiparticles
Antineutrino
The antiparticle of a neutrino
Antiparticle
A particle with the same rest mass and energy as its corresponding particle but equal and opposite charge
Atom
A particle made up of protons and neutrons in a central nucleus and electrons orbiting the nucleus
Atomic number
The number of protons in an atom of an element
Baryon
A type of hardon made up of three quarks
Baryon number
The number of baryons in a particle
Beta-minus decay
A type of decay in which an unstable nucleus of an atom emits a beta-minus particle (an electron) and an antineutrino
Breaking stress
The lowest stress that is big enough to break a material
Brittle
A brittle material doesn't deform plastically but snaps when the stress on it reaches a certain point `
Brittle fracture
When a stress app;lied to a brittle material causes tiny cracks at the materials surface to get bigger until the material breaks completely
Categoric data
Data that can be sorted into categories
Center of mass
The point which you can consider all of an object's weight to act through
Circuit symbol
A pictorial representation of an electrical component
Coherent
Sources that have the same wavelength and frequency and a fixed phase difference between them are coherent
Compressive force
A force which squashes something
Constructive interface
When two waves interfere to make a wave with a larger displacement
Coulomb
A unit of charge. One coulomb is the amount of charge that passes in one second when the current is one ampere
Couple
A pair of forces of equal size which act parallel to each other but in opposite directions
Critical angle
The angle of incidence at which the angle of refraction in 90 degrees
Current
The rate of flow of charge in a circuit, measures in amperes
Continuous data
Data that can have any value on a scale
Density
The mass per unit volume of a material or object
Dependent variable
The cariable that you measure in an experiment
Destructive interference
When two waves interfere to make a wave with a reduced displacement
Diffraction
When waves spread out as they pass through a narrow gap or go round obstacles
Diffraction grating
A slide or other thin object that contains lots of equally spaced slits very close together, used to show diffraction patterns of waves
Diode
A component designed to allow current flow in one direction only.
Directly proportional
A change in ove variable results in a change in the other variable, the changes are always related by the same constant
Discrete data
Data that can only take certain values
Displacement
How far an object has traveled from its starting point in a given direction in the case of a wave, it is the distance a point on a wave has moved from its undisturbed position
Drag
Friction caused by a fluid (gas or liquid)
Efficiency
The ratio of useful energy given out by a machine to the amount of energy put into the machine
Elastic
An elastic material returns to its original shape/length once the forces acting on it are removed
Elastic limit
The force beyond which a material will be permanently stretched
Elastic strain energy
The energy stored in a stretched material
Electromagnetic force
A fundamental force that causes interactions between charged particles. Virtual photons are the exchange particle
Electromagnetic spectrum
A continuous spectrum of all the possible frequencies of electromagnetic radiation
Electromotive force (E.M.F)
The amount of electrical energy a power supply transfers to each coulomb of charge
Electron
A lepton with a relative charge of -1 and a relative mass of 0.0005.
Electron capture
The process of a proton rich nucleus capturing an electron to turn a proton into a neutron, emitting a neutrino
Electron proton collision
The process of an electron colliding with a proton and producing a neutron and a neutrino
Electron volt
The kinetic energy carried by an electron after it has been accelerated through a potential difference of one volt
Equilibrium
An object is in equilibrium if all the forces acting on it cancel each other out
Exchange particle
A virtual particle which allows forces to act in a particle interaction
Excitation
The movement of an electron to a higher energy level in an atom
Fernman diagram
A diagram used to represent particle ineraction
First order line
The first line either side of the zero order line in a diffraction grating interference pattern
First overtone
A resonant frequency of a stationary wave for which the wavelength is the length of the string
Free fall
The potion of an object undergoing an acceleration of g
Frequency
The number of whole wave cycles (oscillations) per seconds passing a given point, Or the number of whole wave cycles given out from a source per second.
Friction
A force that opposes motion. It acts in the opposite direction to the motion. It arises when two objects are moving past each other, or an object is moving througha fluid.
Fundamental frequency
A resonant frequency of a stationsry wave for which the wavelength is double the length of the string
Fundamental particle
A particle which cannot be split up into smaller particles
Gravitational force
A fundamental force which causes attraction between objects with a force proportional to their mass
Gravitational potential energy
The energy an object gains when lifted up
Ground state
The lowest energy level of an atom
Hadron
A particle that is affected by the strong nuclear force
Hooke's law
The extension of a stretched object is proportional to the load or force applied to it, up to the limit of proportionality.
Hooke's law limit
The point beyond which force is no longer proportional to extension. Also known as the limit of proportionality
Hypothesis
A specific testable statement based on a theory about what will happen in a test situation
Independent variable
The variable that you change in an experiment
Interference
The superposition of two or more waves
Internal resistance
The resistance created in a power source when the electrons collide with atoms inside the power source
Ionisation
The process where an electron is removed from to an atom
Ionisation energy
The energy required to remove an electron from an atom
Isotope
An isotope of an element has the same proton number as the element but a different nucleon number
I-V characteristic
A graph which shows how to current flowing through a component changes as the potential difference across it is increased
Kinetic energy
the energy possessed by a moving object
Lepton
A fundamental particle that is not affected by the strong nuclear force
Lepton number
The number of leptons in a particle, the lepton number is counted separately for different types of leptons
Level
A structure with a rigid object and a pivot in which an effort force works against a load force
Light-dependent resistor
A resistor with a resistance that depends on the intensity of light falling on it. The resistance decreases with increasing light intensity
Limit of proportionality
The point beyond which force is no longer proportional to extension.
Line spectrum
The pattern of lines produced by photons being emitted or absorbed by electrons moving between energy levels in an atom
Line absorbtion spectrum
A light spectrum with dark lines corresponding to different wavelengths of light that have been absorbed
Line emission spectrum
A spectrum of bright lines on a dark background corresponding to different wavelengths of light that have been emitted from a light source
Longitudinal wave
A wave in which the vibrations are in the direction of travel of the wave
Lost volts
The energy wasted per coulomb overcoming the internal resistance of a power source
Mass
The amount of matter in an object
Mass number
The number of nucleons in an atom of an element
Matter
The name given to all particles
Maximum
The points in an interferance pattern where the intensity is brightest
Meson
A type of hadron made up of a quark and an antiquark
Minimum
The points in an interference pattern where the intensity is lowest
Model
A simplified picture of representation of a real physical situation
Moment
The turning effect of a force around a turning point
Monochromatic
A light source that is all of the same wavelength
Nucleon
A particle in the nucleus of an atom
Nucleon number
The number of nucleons in an atom of an element
Nucleus
The centre of an atom containing protons and neutrons
Neutrino
A lepton with almost zero mass and zero charge
Neutron
A neutral baryon with a relative mass of one
Newton's first law of motion
The velocity of an object will not change unless a resultant force acts on it
Newton's second law of motion
The acceleration of an object is proportional to the resultant force acting on it
Newton's third law of motion
If an object A exerts a force on object B them object B exerts an equal but opposite force on object A
Ohm's law
Provided the temperature is constant the current through an ohmic conductor is directly proportional to the potential difference across it
Ohmic conductor
A component that has a fixed resistance for a particular temperature
Optical density
The propery of a medium that describes how fast light travels through it. Light moves slower through a medium with a higher optical density
Optical fibre
A thin flexible tube of glass of plastic that can carry light signals using total internal reflection [Show Less]