A bitumen: a mixture of hydrocarbons and other substances that occurs naturally or is obtained by distillation from coal or accelerated : nonuniform motion that involves change in an object’s or direction or both : rate of change of C acceleration due to : the vector 9.8 m/s2 [down], represented by the symbol g cataract: opaque, cloudy that develops in a normally clear : the total effect of produced in an enclosed coupled device: (CCD) a -sensitive device used to store data active solar heating: the process of absorbing the ’s and converting it into other forms of energy chromatic : coloured fringes around objects viewed through alternating : (AC) results when charges periodically reverse direction circuit: a path for ammeter: a device that measures the amount of electric cur- closed air column: column closed at one end and open at the rent in a circuit other : (A) the SI unit of electric current, 1 A = 1 C/s coefficient of : ratio of the of friction to the magnitude of the : from the equilibrium to max- imum coefficient of kinetic friction: ratio of the magnitude of kinetic friction to the magnitude of the of incidence: (vi) the angle between the incident and the normal coefficient of friction: ratio of the magnitude of the maximum static friction to the magnitude of the normal force angle of : (vr) the angle between the reflected ray and the normal cogeneration: the process of producing and using the resulting thermal energy for heat angle of : (vR) the angle between the refracted ray and the normal : region in a longitudinal where the particles are closer together than normal antinode: midway between the nodes where maximum constructive interference occurs conduction: the process of transferring heat through a material by the of arc: light produced by air when a current jumps a gap in an electric circuit conductor: solid in which charge flows freely : a pivoted bar of soft consonance: combinations of of specific that are pleasing to the ear; the frequencies are often in a : eye defect in which the or the lens of the simple ratio eye is not perfectly spherical constructive interference: occurs when build each other : the air in a specific place that can be used as a up, resulting in the medium having a larger amplitude source of heat : the process of transferring heat by a circulating : sub-microscopic particle of which all is made path of particles average acceleration: change of velocity divided by the conventional current or electric current: describes electric interval for that change charges travelling through a conductor from the positive ter- average speed: total distance of travel divided by total time of minal to the negative terminal of the source of electric travel converging lens: lens that causes parallel light rays to come average velocity: change of position divided by the time together so that they cross at a single focal point interval for that change : (C) the SI unit of Coulomb’s Law: The magnitude of the force between two B charged objects is directly proportional to the product of the : unit from which other units are derived or made up charges and inversely proportional to the square of the distance between them. : the number of beats heard per in crest or positive pulse: high section of a wave beats: periodic changes in sound caused by interfer- ence between two nearly identical sound waves critical angle: (vc) the angle in an optically denser medium at which total internal reflection occurs; at this angle the angle of biomass energy: the chemical stored in plants refraction in the less dense medium is 90° and animal wastes cycle: one complete or

582 Glossary D difference: (V ) the amount of required per unit charge to move a positive charge from one point to : (dB) unit used to measure sound intensity level another in the presence of an electric (0 dB = 10–12 W/m2) : object that exerts a magnetic force using elec- derived unit: unit that can be stated in terms of the seven base tricity units electromagnetic force: force caused by electric charges destructive interference: occurs when waves diminish one : negatively charged particle which moves around the another and the amplitude of the medium is less than it would nucleus of an atom have been for either of the interfering waves acting alone electron flow: a term used to indicate that the electric current diamagnetic: materials that cause a very slight decrease in the in metals is due to the motion of of a coil electroscope: device that is used to detect the presence of an : the effect on a wave’s direction as it passes electric charge and to determine the charge’s “sign” (that is, through an opening or by an obstacle whether it is positive or negative) digital : camera that uses digital instead of electrostatic series: chart that shows a substance’s tendency to film to capture or lose electrons : atoms of ferromagnetic substances that act like tiny elementary charge: (e) electric charge of magnitude equal to the charge on a and an electron : (DC) results when charges flow in a particular elements: the components of an electric circuit direction energy: the capacity to do work : the spreading of light into a of colours energy resource: raw material obtained from that can be used to do work displacement: change in position of an object in a given direction energy transformation: the change from one form of energy to another dissonance: combinations of sounds of specific frequencies that have a harsh effect; the frequencies are not in a simple energy transformation or energy converter: a ratio system that converts energy from some source into a usable form diverging lens: lens that causes parallel light rays to spread equivalent resistor: resistor that has the same current and apart so that they appear to emerge from the virtual focal point potential difference as the resistors it replaces : when a source of sound approaches an observer, the observed frequency increases; when the source F moves away from an observer, the observed frequency ferromagnetic: a substance that can become magnetized decreases first law of motion: If the acting on an object is zero, doubling time: the time required for an amount to double the object will maintain its state of rest or constant velocity. : the study of the causes of motion fixed-end reflection: reflection from a rigid obstacle when a pulse is inverted E : (f ) the distance between the principal and : reflected sound waves the optical centre, measured along the principal axis echolocation: location of objects through the analysis of focal : the plane, to the principal axis, on reflected sound. which all focal points lie eddy currents: induced currents that form closed loops within focal point: (waves) a specific place where straight waves are a conductor reflected to; (optics) the position where parallel incident rays meet, or appear to come from, after they pass through a lens efficiency: the ratio of the useful energy provided by a device to the energy required to operate the device force: a push or a pull electric charge: a basic property of matter described as nega- : space surrounding an object in which the object tive or positive exerts a force on other objects placed in the space : the space around a charged object where : relative to which a of attraction or repulsion act on other objects motion can be observed : a device that converts the mechanical free-body diagram: (FBD) drawing in which only the object energy of motion into electrical energy being analyzed is drawn, with arrows showing all the forces acting on the object

Glossary 583 free-end reflection: reflection where the new medium is free to I move and there is no number of cycles point: point at which light from an object point converges frequency: (f ) the number of cycles per second f = total time incident ray: the approaching ray of light friction: force between objects in contact and parallel to con- tact surfaces index of refraction: (n) the ratio of the in a (c) to the speed of light in a given material (v); n = c f-stop number: the ratio of the focal length of the lens to the v f induced charge separation: distribution of charge that results of the ; f-stop = d from a change in the position of electrons in an object fuel cell: device that changes chemical potential energy directly into electrical energy induced field: the magnetic field produced by the induced current fundamental forces: forces are classified into four categories— gravitational, electromagnetic, strong nuclear, and weak inducing field: the magnetic field that causes the induced nuclear current : the property of matter that causes a body to resist : (f0) the lowest natural frequency changes in its state of motion fundamental laws of electric charges: Opposite charges attract each other. Similar electric charges repel each other. Charged infrasonic: any sound with a frequency lower than the objects attract some neutral objects. threshold of human hearing (approximately 20 Hz) fundamental mode: simplest mode of vibration producing the in : objects are vibrating in phase if they have the same lowest frequency period and pass through the rest position at the same time. instantaneous acceleration: acceleration at a particular instant G instantaneous speed: speed at a particular instant : device used to measure the magnitude and instantaneous velocity: velocity that occurs at a particular direction of small electric currents instant : solid that hinders the flow of charge general of Snell’s law: n1 sin v1 = n2 sin v2 geothermal energy: thermal energy or heat taken from beneath ’s J glaucoma: eye defect in which the is damaged : (J) the SI unit for work strength: the amount of force per unit acting on objects in the gravitational field K gravitational force or force of gravity: force of attraction kilowatt hour: (kW•h) the energy dissipated in exactly 1 h by a between all objects load with a of exactly 1 kW gravitational potential energy: the energy possessed by an : the study of motion object because of its position relative to a lower position : the energy possessed by an object due to its : a connection of an object to Earth through a conductor motion kinetic friction: the force that acts against an object’s motion H in a direction opposite to the direction of motion : whole-number multiples of the fundamental fre- Kirchhoff’s current law: (KCL) At any junction point in an quency electric circuit, the total electric current into the junction is heat: the transfer of energy from a warmer body or region to a equal to the total electric current out. cooler one Kirchhoff’s law: (KVL) Around any complete path heat pump: a device that uses evaporation and condensation to through an electric circuit, the sum of the increases in electric heat a home in winter and cool it in summer potential is equal to the sum of the decreases in electric potential. hertz: 1 Hz = 1 cycle/s or 1 Hz = 1 s–1, since cycle is a counted quantity, not a measured unit L hydraulic energy: energy generated by harnessing the potential lateral displacement: sideways shifting of the path of a energy of refracted ray hydrocarbons: compounds that contain only carbon and law of conservation of charge: Electric charge is neither cre- ated nor lost in an electric circuit, nor does it accumulate at hyperopia: eye defect in which nearby images are not seen any point in the circuit. clearly; also called farsightedness

584 Glossary law of : When energy changes from one Magnetic : (MRI) diagnostic technique form to another, no energy is lost; (electricity) as electrons that produces high- images of soft tissue inside the body move through an electric circuit they gain energy in sources magnetic : occurs when the maximum amount of and lose energy in loads, but the total energy gained in one trip dipoles in a material are aligned through a circuit is equal to the total energy lost. mass: the quantity of matter in an object law of electromagnetic induction: An electric current is : the sum of the gravitational potential induced in a conductor whenever the magnetic field in the energy and the kinetic energy region of the conductor changes. : instrument that produces enlarged images of law of magnetic : opposite magnetic poles attract; similar objects too small to be seen by the unaided eye magnetic poles repel motor principle: A current-carrying conductor that cuts across law of universal gravitation: The force of gravitational attrac- external magnetic field lines experiences a force perpendicular tion between any two objects is directly proportional to the to both the magnetic field and the direction of electric current. product of the of the objects, and inversely propor- The magnitude of this force depends on the magnitude of both tional to the square of the distance between their centres. the external field and the current, as well as the angle between laws of reflection: The angle of incidence is equal to the angle the conductor and the magnetic field it cuts across. of reflection. The incident ray, the reflected ray, and the normal music: sound that originates from a source with one or more all lie in the same plane. constant frequencies laws of refraction: The ratio of sin v to sin v is a constant i R mutual induction: an effect that occurs whenever a changing (Snell’s law). The incident ray and the refracted ray are on current in one coil induces a current in a nearby coil opposite sides of the normal at the point of incidence, and all three are in the same plane. : eye defect in which distant objects are not seen clearly; also called nearsightedness lens: transparent device with at least one curved surface that changes the direction of light passing through it lens camera: light-proof box inside which a converging lens N directs light onto a film to capture a negative ion: an atom that has at least one extra electron and is Lenz’s law: For a current induced in a coil by a changing mag- negatively charged netic field, the electric current is in such a direction that its : a found in the nucleus own magnetic field opposes the change that produced it. : (N) the SI unit of force light: a form of energy that is visible to the or nodal point: (N) point that remains at rest linear propagation: one of the properties of light; describes noise: sound that originates from a source where the frequen- light as travelling in straight lines cies are not constant load: any device in a circuit that transforms electrical potential non-renewable energy resource: an energy resource that does energy into some other form of energy, causing an electric not renew itself in the normal human lifespan potential nonuniform motion: movement that involves change in speed local consumption: generating energy locally to avoid the or direction or both transfer of energy over long using transmission lines normal: (waves) a straight drawn perpendicular to a bar- longitudinal vibration: occurs when an object vibrates parallel rier struck by a wave; (optics) the line drawn at right to to its axis the reflecting surface at the point of incidence : particles vibrate parallel to the direction of normal force: force perpendicular to the surfaces of the objects motion of the wave in contact N-pole: the end of a that seeks the northerly direction M : process in which the nucleus of each atom Mach number: the ratio of the speed of an object to the speed splits and releases a relatively large amount of energy speed of object of sound in air; Mach number = nuclear fusion: the process in which the nuclei of the atoms of : formed by a group of dipoles lined up with light elements join together at extremely high to their magnetic axes in the same direction become larger nuclei magnetic field of force: the space around a magnet in which nucleus: the central region of an atom, where and magnetic forces are exerted are found magnetic induction: the process of magnetizing an object from a distance

Glossary 585 O0 power: (P) the rate of doing work or transforming energy, or the rate at which energy is used or supplied : in an , the lens closest to the object : eye defect in which the lens in the eye loses elas- object point: a point representing a source of rays, whether by ticity; a type of farsightedness production or reflection primary : the rainbow of visible spectral colours that octave: sounds that differ in frequency by a factor of two results from a single internal reflection in rain drops ocular: in an optical instrument, the lens the eye looks into principal axis: (PA) a horizontal line drawn through the : () the SI unit for electric resistance optical centre Ohm’s law: The potential difference between any two points in principal focus: (F) the point on the principal axis through a conductor varies directly as the current between the two which a group of rays parallel to the principal axis is refracted points if the remains constant. principle of : Whenever an electric current open air column: column open at both ends moves through a conductor, a magnetic field is created around optical axis: (OA) a vertical line through the optical centre the conductor. optical centre: (O) the geometric centre of all lenses principle of heat exchange: When heat is transferred from one body to another, the amount of heat lost by the hot body out of phase: objects are vibrating out of phase if they do not equals the amount of heat gained by the cold body. have the same period or if they have the same period but they do not pass through the rest position at the same time. principle of superposition: At any point the resulting ampli- tude of two interfering waves is the algebraic sum of the dis- : the resulting modes of vibration when a string placements of the individual waves. vibrates in more than one segment emitting more than one frequency : a transparent solid that has at least two plane refracting surfaces proton: positively charged particle found in the nucleus of an P atom parallel circuit: circuit in which charges can move along more pulse: wave that consists of a single disturbance than one path pure tone: a sound that consists of one frequency paramagnetic: material that magnetizes very slightly when placed in a coil and increases the field strength by a barely measurable amount Q partial reflection: some of the energy is transmitted into the quality of a musical note: a property that depends on the new medium and some is reflected back into the original number and relative intensity of harmonics that make up the medium sound partial reflection and refraction: a of light splitting into two rays; one is reflected; the other is refracted R passive solar heating: the process of designing and building a : the process in which energy is transferred by means structure to take best advantage of the Sun’s energy at all of electromagnetic waves of the year rarefaction: region in a longitudinal wave where the particles totaltime period: (T) the time required for one cycle T = number of cycles are farther apart than normal periodic motion: motion that occurs when the vibration, or ray: the path taken by light energy oscillation, of an object is repeated in equal time intervals reference level: the level to which an object may fall periodic waves: originate from periodic where the are continuous and are repeated in the same time reflected ray: the ray of light reflected from the reflecting sur- intervals face pitch: the of the highness or lowness of a sound; reflecting : telescope that uses a parabolic to depends primarily on the frequency of the sound focus light pixel: image-forming unit : telescope that uses two converging lenses to focus light point of incidence: the point at which the incident ray strikes the reflecting surface refraction: (waves) the bending effect on a wave’s direction that occurs when the wave enters a different medium at an poles: of concentrated magnetic force angle; (optics) the change in direction of light as it passes from position: the distance and direction of an object from a refer- one medium into another of differing ence point relative magnetic permeability: (K) the factor by which a positive ion: an atom that has lost at least one electron and is material increases the magnetic field strength that would exist positively charged in the same region if a vacuum replaced the material

586 Glossary : velocity of a body relative to a particular : a coil of wire that acts like a magnet when an electric frame of reference current passes through it : a device in which a is closed by the of an : system that uses transmitted and reflected underwater electromagnet sound waves to locate objects or measure the distance to the renewable energy resource: an energy resource that renews bottom of the water body itself in the normal human lifespan : an explosive sound that radiates from an aircraft resistance: an opposition to the flow of charge, resulting in a travelling at supersonic loss of potential energy sound: a form of energy, produced by rapidly vibrating objects, resonance or mechanical resonance: the transfer of energy that can be heard by the human ear from one object to another having the same natural frequency sound barrier: a high- region produced as an airplane : an object, usually a hollow chamber, that vibrates in approaches a speed of Mach 1 resonance with a source of sound sound intensity: power of a sound per unit area in per resultant displacement: vector sum of the individual displace- squared ments specific heat capacity: (c) a measure of the amount of energy or net force: the vector sum of all the forces needed to raise the temperature of 1.0 kg of a substance by 1.0°C acting on an object speed of light: (c) the speed of light in a vacuum with a value × 8 reverberation time: the time required for the intensity of the of 299 792 458 m/s, or 3.00 10 m/s sound to drop to 10–6 (one millionth) of its original value or S-pole: the end of a magnet that seeks the southerly direction until the sound is inaudible : created when waves travelling in opposite rheostat: device in an electric circuit that can be adjusted to directions have the same amplitude and different resistances, changing the current in the circuit starting friction: the amount of force that must be overcome right-hand rule for a coil: If a coil is grasped in the right hand to start a stationary object moving with the curled fingers representing the direction of electric : a build up of stationary electric charge on a current, the thumb points in the direction of the magnetic field substance inside the coil. static friction: the force that tends to prevent a stationary right-hand rule for a conductor: If a straight conductor is held object from starting to move in the right hand with the right thumb pointing in the direc- step-down : a transformer with fewer windings on tion of the electric current, the curled fingers will point in the the secondary coil, resulting in decreased voltage direction of the magnetic field lines. step-up transformer: a transformer with more windings on right-hand rule for the motor principle: If the fingers of the the secondary coil, resulting in increased voltage open right hand point in the direction of the external magnetic field, and the thumb represents the direction of electric cur- strong : force that holds protons and neutrons rent, the force on the conductor will be in the direction in together in the nucleus of an atom which the right palm faces. subsonic speed: speed less than the speed of sound in air supercrest: occurs when a crest meets a crest S supersonic speed: speed greater than the speed of sound in air quantity: quantity that has magnitude, but no direction supertrough: occurs when a trough meets a trough second law of motion: if the net external force on an object is switch: a device that is used to make or break an electric circuit not zero, the object accelerates in the direction of the net force, sympathetic vibration: the response to a vibration with the with magnitude of acceleration proportional to the magnitude same natural frequency of the net force and inversely proportional to the object’s mass system diagram: sketch of all the objects involved in a situation semiconductor: material used to transmit and amplify elec- tronic T series circuit: circuit in which charges have only one path to follow parallel circuit: circuit in which charges can move along : a straight line that touches a curve at a single point more than one path and has the same slope as the curve at that point single-lens reflex (SLR) camera: camera that uses a single lens tangent technique: a method of determining velocity on a and a movable mirror position-time graph by drawing a line tangent to the curve and Snell’s law: The ratio of the of the angle of incidence to calculating the slope the sine of the angle of refraction is a constant. temperature: a measure of the average kinetic energy of the solar energy: from the Sun atoms or molecules of a substance : force exerted by string, ropes, fibres, and cables

Glossary 587 terminal speed: maximum speed of a falling object at which uniform magnetic field: the magnetic field is the same point the speed remains constant and there is no further accel- strength and acts in the same direction at all points eration uniform motion: movement at a constant speed in a straight terrestrial telescope: telescope that is similar to a refractor, but line with the of a third lens, the erector lens, to obtain universal : v = f l upright images thermal energy: the total kinetic energy and potential energy V of the atoms or molecules of a substance equation: the quantitative relationship for thin lenses; vector quantity: quantity that has both magnitude and 1 + 1 = 1 direction do di f third law of motion: for every action force, there is a velocity: the rate of change of position force equal in magnitude, but opposite in direction point: point from which rays from an object tidal energy: energy generated by harnessing the gravitational point appear to diverge forces of the and the Sun that act on Earth : (V) the SI unit for electric potential difference; 1 V = 1 J/C torsional vibration: occurs when an object twists around its voltmeter: a device that measures electric potential difference axis between two points in a circuit total internal reflection: the reflection of light in an optically denser medium; it occurs when the angle of incidence in the W more dense medium is equal to or greater than a certain crit- ical angle : (W) the SI unit for power transformer: device that consists of a core of soft iron with wave: a transfer of energy over a distance, in the form of a dis- two separate coils of wire used to change the voltage turbance transverse vibration: occurs when an object vibrates perpendi- : the leading edge of a wave cular to its axis : occurs when two or more waves act simul- : particles in the medium move at right angles taneously on the same particles of a medium to the direction in which the wave travels wavelength: (l) distance between successive wave particles that trough or negative pulse: low section of a wave are in phase turbine: in which the kinetic energy of a moving fluid wave ray: a straight line drawn perpendicular to a wavefront is converted to rotary mechanical power that indicates the direction of transmission weak nuclear force: force responsible for involving elementary particles such as protons and neutrons U : the force of gravity on an object ultrasonic: any sound with a frequency above the range of wind energy: energy generated by harnessing the kinetic human hearing (approximately 20 000 Hz) energy of wind uniformly accelerated motion: motion that occurs when an work: the energy transferred to an object by an applied force object travelling in a straight line changes its speed uniformly over a measured distance with time

588 Glossary