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Contents

Amusement park physics . . . . . . . . .1

Car audio . . . . . . . . . . . . . . . . . . . . .22

Cars—speed and safety . . . . . . . . .47

Crime scene physics . . . . . . . . . . . .70

Discovering the Solar System . . . .93

Electronic devices . . . . . . . . . . . . .113

Medical physics . . . . . . . . . . . . . . .135

Movie magic . . . . . . . . . . . . . . . . . .155

Physics in the home . . . . . . . . . . .176

Rocket science . . . . . . . . . . . . . . . .202

Sport . . . . . . . . . . . . . . . . . . . . . . . .232

The search for understanding . . .251

The sounds of music . . . . . . . . . . .273

Visiting the reef . . . . . . . . . . . . . . .294

1 Acceleration . . . . . . . . . . . . . . .319

2 Atomic structure . . . . . . . . . . .323

3 Bernoulli’s principle . . . . . . . .330

4 Buoyancy . . . . . . . . . . . . . . . . .334

5 Capacitors and inductors . . .338

6 Centre of mass . . . . . . . . . . . . .345

7 Charge and Coulomb’s law . .347

8 Circular motion . . . . . . . . . . . .350

9 Collisions . . . . . . . . . . . . . . . . .352

10 Critical velocity . . . . . . . . . . . .358

11 Density . . . . . . . . . . . . . . . . . . .360

12 Direction . . . . . . . . . . . . . . . . .363

13 Electric fields and potential . .365

14 Electricity . . . . . . . . . . . . . . . . .371

15 Electromagnetic spectrum . .377

16 Energy and work . . . . . . . . . . .379

17 Equations of motion . . . . . . . .384

18 Equilibrium . . . . . . . . . . . . . . .386

19 Escape velocity . . . . . . . . . . . .387

20 Fluid flow . . . . . . . . . . . . . . . . .388

Contexts

Key Ideas

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21 Friction . . . . . . . . . . . . . . . . . . .392

22 Gravity . . . . . . . . . . . . . . . . . . .395

23 Heat and its effects . . . . . . . . .399

24 Heat and temperature . . . . . .403

25 Hooke’s law . . . . . . . . . . . . . . .407

26 Ideal gas laws . . . . . . . . . . . . . .410

27 Kinetic energy . . . . . . . . . . . . .419

28 Kinetic theory of a gas . . . . . .421

29 Kirchhoff’s rules . . . . . . . . . . .426

30 Lasers . . . . . . . . . . . . . . . . . . . .429

31 Latent heat . . . . . . . . . . . . . . . .432

32 Lenses . . . . . . . . . . . . . . . . . . . .434

33 Magnetic fields . . . . . . . . . . . .445

34 Magnetic forces . . . . . . . . . . . .450

35 Magnetism and electromagnetic induction . .456

36 Mass and weight . . . . . . . . . . .463

37 Mass–energy equivalence . . .465

38 Mirrors . . . . . . . . . . . . . . . . . . .468

39 Momentum and impulse . . . .480

40 Newton’s first law of motion .483

41 Newton’s second law of motion . . . . . . . . . . . . . . . . . . .486

42 Newton’s third law of motion 488

43 Nuclear fission . . . . . . . . . . . . .489

44 Nuclear fusion . . . . . . . . . . . . .492

45 Nuclear radiation . . . . . . . . . .494

46 Pascal’s principle . . . . . . . . . . .498

47 Pendulum . . . . . . . . . . . . . . . . .501

48 Photoelectric effect . . . . . . . . .504

49 Potential energy . . . . . . . . . . .509

50 Power—electrical . . . . . . . . . .513

51 Power—mechanical . . . . . . . .516

52 Pressure . . . . . . . . . . . . . . . . . .518

53 Quantum theory . . . . . . . . . . .523

54 Radioactive decay . . . . . . . . . .525

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55 Relativity . . . . . . . . . . . . . . . . . .531

56 Rotational motion . . . . . . . . . .536

57 Semiconductors . . . . . . . . . . .540

58 Simple harmonic motion . . . .545

59 Simple machines . . . . . . . . . . .549

60 States of matter . . . . . . . . . . . .555

61 Terminal velocity . . . . . . . . . . .557

62 Units . . . . . . . . . . . . . . . . . . . . .559

63 Vectors . . . . . . . . . . . . . . . . . . .563

64 Velocity . . . . . . . . . . . . . . . . . . .570

65 Vertical and projectile motion . . . . . . . . . . . . . . . . . . .572

66 Waves and refraction . . . . . . .579

67 Waves and the Doppler effect . . . . . . . . . . . . . . . . . . . . .586

68 Waves and their speed . . . . . .588

69 Waves in one dimension . . . .594

70 Waves in two dimensions . . .601

71 Wave–particle duality . . . . . . .608

Appendix A . . . . . . . . . . . . . . . . . .609

Appendix B . . . . . . . . . . . . . . . . . .613

Appendix C . . . . . . . . . . . . . . . . . .614

Answers . . . . . . . . . . . . . . . . . . . . .615

Index . . . . . . . . . . . . . . . . . . . . . . . .624

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The following five Key Ideas can be found on the ePhysics CD:

Graphs and tables

Mathematical skills

Measurements and calculations

Problem solving

Writing scientific reports

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Heinemann Queensland Science Project—Physics: A Contextual Approachpresents physics in a variety of real-world contexts and is designed to supportthe new Queensland 2004 Physics Syllabus. It is also suitable for other physicscourses requiring a contextual approach.

The single textbook for both years 11 and 12 provides flexibility ofplanning, enabling topics to be selected and studied in an order that suits theteachers and students.

The organisation of the new Queensland 2004 Physics Syllabus involvesplanning courses of study that focus on general objectives categorised asScientific Investigation, Scientific Techniques and Knowledge, and ConceptualUnderstanding. Twelve key concepts are the foundation stones of the syllabus,organised into three themes: force, energy and motion. Any course of studymust allow students to develop an understanding of these key conceptsembedded in real-world contexts. The key concepts are broad statementsconcerning the fundamental knowledge underpinning physics. These areexplored using key ideas, which include simple definitions, formulae andtheories familiar to teachers and students of physics. A number of key ideasconsidered essential to the development of the key concepts are suggested bythe syllabus, but teachers are offered the opportunity to expand on thesewhere necessary.

Heinemann Queensland Science Project—Physics: A Contextual Approach

Physics: A Contextual Approach is structured in two parts: • Contexts—These are the starting point for the development of a course of

study. Physics ideas and concepts are explored in real-life situations. Physicsideas that are specific to a particular situation are developed in detail.

• Key Ideas—Many physics ideas find application in a variety of contexts.These are developed separately in a non-context-specific way.

The ContextsThe Contexts are linked to the Key Ideas within the chapters via clearreferences. Investigations and other activities within a Context are aimed atproviding practice or assessment opportunities according to the assessmentcategories of the syllabus. As students engage with these activities they willdevelop a greater understanding of the key concepts and key ideas from thesyllabus.

Teaching in context means that assessment should also be in context. In the2004 Syllabus, three categories of assessment are identified:• Extended Experimental Investigation• Written Test• Extended Response Task.Activities within the Contexts have the potential to be used for assessment andare categorised accordingly.

Introduction......................................................

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The Key IdeasThe Key Ideas contain the physical concepts and ideas essential to understandingthe key concepts. They include clearly presented formulas, definitions and workedexamples. Opportunities to use Practical Activities and Interactive Tutorials aresignposted. Each Key Idea has related questions, drawn from a variety of Contexts,and answers to these are included in the text.

ePhysics

The ePhysics student CD consists of an electronic version of the textbook, PracticalActivities for students and fully Interactive Tutorials which model and simulate keyphysics concepts.

Physics: A Contextual Approach Teacher’sResource and Assessment Disk

The Teacher’s Resource and Assessment Disk includes a copy of the ePhysics studentCD, fully worked solutions to the exercises in the Contexts and to the questions inthe Key Ideas, experimental notes and safety advice, overhead transparencytemplates, sample course outlines and sample assessment items. Additionalcontext scaffolds and course outlines are also offered.

Importantly, sample course outlines demonstrate a number of different waysof incorporating the requirements of the syllabus into a course of study presentedover years 11 and 12.

Physics: A Contextual Approach can be used as a resource for teachers andstudents as they plan for, and work through the selected contexts. Sampleassessment tasks are provided for the categories Extended Response Task andExtended Experimental Investigation. Sample criteria sheets for each of these tasksdemonstrate how the criteria can be individualised for each assessment task, butstill link closely with the standards associated with the exit levels of achievementin the syllabus.

About the authors

David MaddenDavid has taught senior physics and mathematics and junior science in a variety of school settingsin Queensland for over ten years. He has been a member of a number of QSA District ReviewPanels over the last six years. David is currently Head of Science at the Scots Presbyterian Girl’sCollege in Warwick. Scots has been a Trial-Pilot school for the last three years and will be a part ofthe Extended Trial-Pilot through to 2007. David has presented a number of seminars based on hisexperience of teaching physics in context at CONASTA and QSA Physics Trial-Pilot conferences.He has also been a major contributor to the website of the Physics Trial-Pilot(http://www.mbc.qld.edu.au/physics/wp.html). David has a particular interest in the use of validassessment in context. His other interests include cricket, AFL and playing the piano.

Tyson StelzerTyson Stelzer’s interest in physics textbooks began at the tender age of twelve, when it is alleged,he read his first volume. His interest in the field grew from this point culminating in a Bachelor ofScience degree in physics, a Bachelor of Arts degree in mathematics and biblical studies, and aDiploma in Education. Today, at the age of 29, Tyson has had seven years experience as aninnovative physics teacher at Trinity Lutheran College on the Gold Coast and now serves as Headof Senior Science. He has been widely published within the Australian wine industry, with a

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particular emphasis on the technicalities of wine science. Tyson enjoys photography, playingguitar and sax in his church band, building and restoring furniture, roller blading and listening toloud music in his car.

Ian LindsayIan has 21 years experience as a secondary science and mathematics teacher. He has continuouslybeen involved in curriculum design and delivery at a whole school level as well as at the subjectlevel in senior physics and junior and senior mathematics. Ian has been coordinator of physics atRuncorn State High School for the last 16 years and in this capacity has been a member of the QSAPhysics District Review Panel for seven years. Ian has always sought to deliver physics in anengaging and relevant way, and endeavoured to have his students experience the joy ofunderstanding. His interests include music, reading, tennis and the very occasional playing of theflute.

Darryl ParsonsDarryl Parsons [BScEd, GradDipScEd, GradDipEd(Mgt), GradDipEd, BAppSc, JP] has taught juniorscience, maths, and senior chemistry and physics in Queensland schools for twenty years. He hasserved on the QSA Physics and Chemistry District Panels for seven years, has been Science Master,Assistant Principal and Head of Curriculum, and is currently the Principal of the HillsInternational College in Jimboomba, Queensland. He is working on a doctorate in scienceeducation which he has been saying he will ‘finish soon’ for the last three years!

Tracy GazeTracy has twelve years experience as an educator in secondary science and mathematics, havingtaught in south-west Queensland, northern Queensland and Wide Bay (Queensland). With acommitment to criteria-based assessment and the development of student skills, she wasinvolved in developing the junior and senior mathematics and science curricula for a newindependent school in Hervey Bay. This involvement included five years with sole responsibilityfor the physics program at Fraser Coast Anglican College, together with membership of the QSAWide Bay District Review Panel for Physics. Tracy has also undertaken study in psychology, andmaintains a strong interest in student development.

Acknowledgments

The publisher would like to thank and acknowledge the following people for their contribution tothis book:Marianne Hammat for her contribution to the structure and organisation of the book, managementof this project, fine editorial work and unwavering commitment to this complex and challengingproject.Brigid Brignell for her professional and committed management of the project.Julia Balcombe for her tireless contribution to the running and management of the project.

David MaddenTo Karen, Jessie and Reuben, thank you for all your support and encouragement. To my Mum andDad, thanks for giving me a love of learning and encouraging me to ask questions.

Ian LindsayThanks to Merv Swords for getting me involved in the co-writing of this book, to MatthewSatterthwaite and Chris Godde for their practical help, and to all those who displayed patiencewhile I progressed through the stages of publishing this book. Specific thanks to my great kids,Jarrah and Nerida, who have been most patient, and also to PK for her encouragement and support.May I dedicate my portion of this book to Col Martin whose infectious enthusiasm for knowledgeand understanding made him such a great teacher.

Darryl ParsonsThanks to my wife Robyn for letting me disappear into my home office for extended periods over thelast two years when I should have been fixing the boat.

Tracy GazeThanks to Mr Greg Lynch, Head of Department (Science) and marine studies teacher at Fraser CoastAnglican College, for his support and assistance during the writing process for the context, ‘Visitingthe Reef ’.

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Practical Activities and Interactive Tutorials

The following Practical Activities and Interactive Tutorials can be found on the ePhysics student CDaccompanying this textbook.

Practical Activities01 Disturbance and propagation of a

disturbance 02 Waves in a Slinky 03 Waves in a rope04 The speed of sound by clap and

echo 05 Waves in a ripple tank 06 Reflection of waves in a ripple

tank 07 Diffraction of continuous water

waves 08 Interference of water waves 09 Reflection in a plane mirror 10 Refraction of continuous water

waves 11 Investigating refraction: Snell’s law 12 Total internal reflection in prisms 13 Colour addition and subtraction 14 Light and a continuous spectrum 15 Polarisation effects with light 16 Concave mirrors 17 Convex lenses 18 Audio transmission with a light

beam 19 Newton’s particle model of light 20 Diffraction of light 21 Interference of light: Young’s

double slits 22 Photoelectric effect 23 Internal resistance of a battery 24 Characteristics of diodes 25 Transistors as amplifiers 26 Solar cell’s response to light 27 Investigating resistors 28 Charge and time constant of

capacitors 29 RC circuits 30 Rectifier circuits 31 Using a zener diode 32 Voltage regulators 33 Specific heat capacity of a metal 34 Power of a tea light 35 Latent heat of fusion of water 36 Specific heat capacity of a brick 37 Solar cooker 38 Solar hot water heater 39 Water purification unit 40 Pitch, loudness and quality 41 Visualising standing waves in air

columns 42 Speed of sound by resonance tube 43 Frequency response of a

loudspeaker 44 Interference of sound 45 Kinematics of a student 46 The ticker timer 47 Analysing motion with a motion

sensor 48 Acceleration down an incline 49 A reaction timer

50 Force and equilibrium 51 Newton’s second law 52 Newton’s second law II 53 Conservation of energy 54 Conservation of momentum in

explosions 55 Locating the centre of mass 56 Velocity–time graphs 57 Action and reaction 58 Motion on an inclined plane 59 Projectile motion 60 Conservation of momentum in

collisions 61 Conservation of energy in springs 62 Hooke’s law: Determining k for a

spring 63 Centripetal force 64 Acceleration due to gravity 65 Frames of reference 66 Relative motion 67 Time dilation 68 The Lorentz factor 69 A non-simultaneity simulation 70 Stress and strain in two rubber

bands 71 Forces in a beam 72 The compressive strengths of

materials 73 An investigation of copper wire 74 Forces in a cantilever 75 Locating the centre of gravity 76 Seesaws 77 Electrostatics with a Van der

Graaff generator 78 Connecting circuits 79 Using electrical meters 80 Resistance and temperature 81 Ohmic and non-ohmic

conductors 82 Electrical power 83 Series circuits 84 Parallel circuits 85 Resistance in a combination

circuit 86 Internal resistance of a dry cell 87 Direction of induced current in a

wire 88 Strength of the magnetic field

inside a coil 89 Investigating electromagnetic

induction 90 Faraday’s law of electromagnetic

induction 91 Current from an electric motor 92 Transformer operation 93 Calculating the charge-to-mass

ratio of an electron 94 A collision in two dimensions 95 Observing the photoelectric effect 96 Wavelength of LEDs 97 Optical fibre bend loss 98 Fibre optic cladding

99 A free space optical transmitter 100 Hydroelectric power 101 Sunlight intensity and reflectivity

of Earth’s surface 102 Solar energy: Generating

electricity 1 103 Solar energy: Generating

electricity 2 104 Wind power 105 Solar constant 106 Energy efficiency of a fuel cell107 Detecting radiation with a

Geiger–Müller tube108 The diffusion cloud chamber109 A model of alpha scattering110 An analogue experiment of

radioactive decay111 Ultrasound interactions:

Attenuation of sound112 The Doppler effect113 Diagnostic X-rays114 Watching the night sky115 Measuring the night sky:

alt-azimuth116 Measuring the night sky:

equatorial coordinates117 The Sun in the day sky118 The phases of the moon119 Computer simulation of the

night sky120 Night sky exercises in astronomy121 Distances by parallax

measurement122 The inverse square law123 The Doppler effect II124 Spectra of different elements125 LEA and CLEA

Interactive TutorialsBraking (Video analysis of motion)GeneratorsKilowatt-hoursKinetic and gravitational potential

energyMotorsPhotoelectric effect: Frequency versus

kinetic energyPhotoelectric effect: Investigate

forward and reverse voltagePhotoelectric effect: Investigate light

intensityPhotoelectric effect: Which colours will

work?Radioactive decay and half-lifeRefractionRelative velocitiesSpecific heat of a metalThe wave equationsYoung’s modulus

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