WJEC Physics for A2: Student Bk

5 About this book Margin features The text is supplemented by a number of margin features: Terms & definitions These are physics terms and laws that you need to be able to quote without further information. For example: In the context of laboratory investigations into radioactive sources, background radiation is the nuclear radiation which is detected in the absence of the source under investigation. Terms & definitions Physics examination papers always contain a few marks for defining terms or stating a physical law. St u dy point Some ideas from the main text are further developed in Study points. These are used for material which is important for you to understand but is tangential to the flow of the text. Some Study point boxes include material designed to extend your understanding beyond the requirements of the specification. For example: St u dy point ω always has a positive value so we don’t need to write ω = ± 20 s −1 . Self-test Questions to enable you to check your understanding of the subject at that point in the text. They are often short calculations (though some are longer and some require short verbal analysis), which require you to apply the concepts developed in the main text. The answers to these Self-test questions are given at the end of the book. & S C Stretch & Challenge Material developed in these is designed to make you think more deeply about the subject. They usually include questions for you to consider, discuss and answer. They will be most useful for students intending to progress to higher study in physics or engineering. Unlike the self-test marginalia, the answers to these questions are not provided. MATHS TIP These refer to particular techniques and often direct you to the Mathematical skills section for a fuller treatment. Matching the specification content to the sections in this book Units 3 and 4 in this book are generally arranged to follow the WJEC specification. For example: Section 3.1, Circular motion on pages 70–79 deals with Unit 3 Topic 1 of the WJEC specification, with the same name. However, some areas of physics are related closely to material in more than one unit. The understanding of the nature of electric fields, for example, relates to the content of Unit 4, topics 1 (Capacitors) and 2 (Electrostatic and gravitational fields of force). To facilitate the use of this book, a grid is provided on page 300 to match specification areas to book sections. An extract is shown below. Book Specification page section section title 10 3.1.1 The kinematics of ‘uniform’ circular motion 3.1 a,c,d 12 3.1.2 The existence of a resultant force for an orbiting object 3.1 e,f 13 3.1.3 Centripetal acceleration 3.1 e,f,g 14 3.1.4 Centripetal force 3.1 e,f,g 21 3.2.1 Introduction to simple harmonic motion 3.2 a, c 22 3.2.2 Equations of simple harmonic motion 3.2 b, d 23 3.2.3 Characteristics of simple harmonic motion 3.2 e, f 25 3.2.4 Examples of simple harmonic motion 3.2 i, j 28 3.2.5 Energy of oscillation 3.2 k 29 3.2.6 Damped oscillations 3.2 l, m 29 3.2.7 Forced oscillations 3.2 o, p, q 40 3.3.2 Expressing the amount of substance 3.3 d, e 42 3.3.3 The ideal gas equation 3.3 a 43 3.3.4 The behaviour of molecules in gases 3.3 b 44 3.3.5 Molecular motion and gas pressure 3.3 b, c 47 3.3.6 Molecular energy 3.3 f