Glossary - Vocab Test Flashcards
Absorb
To take up and store energy, without it being reflected or transmitted.
Absolute zero
-273 C or 0 K
Acceleration
The rate of change of velocity
Adsorbed dose
The amount of ionizing. radiation absorbed per kilogram of irradiated material
Absorption line spectrum
A spectrum containing dark lins in the positions of the wavelengths that are absorbed by a gas as light passes through it. ]
Acceleration due to gravity
The rate at which a falling object will accelerate in a gravitational field. Equivalent to the gravitational field strength. It is measured in ms-2 and its symbol is g.
Accuracy
A measurement value is considered to be accurate is it is judged to be close to the true value of the quanitity being measured. Accuracy is a qualitative term; a measurement value or measurment result may be described. for example, as being “less accurate” or “more accurate” when compared with a true value.
aether
An invisible, massless, rigid substance that was proposed as the medium in which light waves propagate. There is no experimental evidence for the existence of the aether.
Aim
A statement describing what will be investigated in an experiment.
Air resistance
A retarding force that acts in the opposite direction to the motion of an object as it passes through the air.
Alternating current
An electric current that periodically reverses direction and with a magnitude that varies over time. Abbreviated to AC. Household power supplies ususally operate at 240V AC.
Alternator
An electric generator that produces an alternating current.
Altitude
The height above an objects’s surface (such as a planet or moon).
Amplitude
The absolute zero of the maximum displacement from zero during one period of one oscillation.
Annihilation
The complete conversion of matter into energy when matter meets its antimatter equivalent. This is not a chemical process, where matter in one form is converted to matter of another form, as occurs in burning.
Anode
A positively charged plate in an electron gun. Electrons are accelerated towards the anode.
Antinode
The region of maximum amplitude between two adjacent nodes in a standing wave or interface pattern.
Armature
A revolving structure in an electric motor or generator that is wound with a coil or coils that carry current. It rotates within a magnetic field to induce an EMF.
Artificial satellite
A body that is made by humans and placed in orbit around a planet or the moon; e.g Sputnik, the Hubble Space Telescope and NOAA-19.
Banked track
A track inclined at an angle to the horizontal. This enables vehicles to corner at higher speeds than if the track were horizontal.
Bias
A form of systematic error resulting from the researcher’s personal preferences or motivations.
Breaking point
The point at which a material cannot be extended any further without it breaking.
Brushes
Devices that transfer the current in the rotating coil to a stationary external circuit by pressing against the split ring commutator or against the slip rings.
Cathode
The filament in a cathode ray tube which, when heated, produces electrons.
Cathode ray tube
The vacuum tube in which a hot cathode emits a beam of electrons that travel towards a high-voltage anode. The beam can be focused or deflected by electrodes that generate an electric field.
Centripetal acceleration
The acceleration directed towards the centre of the circle when an object moves with constant speed in a circular path.
Classical force
The force that causes an object to travel in a circular path, e.g gravity, tension, normal force and friction.
Classical physics
The physics of Galileo and Newton, in which the addition of velocities has no limit, and which treats length and time as fixed properties across all frames of reference. Accurately describes the macroscopic world but becomes inaccurates for things that are very small or moving very fast.
Coherent
Describes waves that have the same frequency and waveform and are either in phase or have a constant phase difference.
Commutator
The part of an electric motor that allows current to be reversed. This enables the coil to keep rotating due to a magnetic force.
Compression
An area of increased pressure within a longitudinal wave.
Conclusion
An evidence-based statement that is developed from an analysis of experimental results.
Conserved
Not created or destroyed, but remaining constant.
Constructive interference
The process by which two or more waves combine to reinforce each other. The amplitude of the resulting wave is equal to the sum of the amplitudes of the superimposed waves.
Continuous variable
A variable that can have any numerical value within a given range.
Controlled variable
A variable which is kept constant in order to reliably find the effect of changing the independent variable.
Crest
The maximum or highest point in a cycle of a transverse wave.
de Broglie wavelength
