Cambridge AssessmentCollinsInternational EducationEndorsed for full syllabus coverageCambridge InternationalAS A Level PhysicsSTUDENT'S BOOKMichael Smyth,Lynn Pharaoh,Richard Grimmer,Chris Bishop and Carol DavenportCollinsCambridge InternationalAS A Level PhysicsSTUDENT'S BOOK代Michael Smyth,Lynn Pharaoh,Richard Grimmer,Chris Bishop and Carol DavenportWilliam Collins'dream of knowledge for all began with the publication of his first book in 1819.A self-educated mill worker,he not only enriched millions of lives,but also founded a flourishing publishing house.Today,staying true to this spirit,Collinsbooks are packed with inspiration,innovation and practical expertise.They place you at the centre of a world of possibility andgive you exactly what you need to explore it.Collins.Freedom to teachPublished by CollinsAn imprint of HarperCollinsPublishersThe News Building1 London Bridge StreetLondonSE1 9GFBrowse the complete Collins catalogue atCambridge International copyright material in this publicationwww.collins.co.ukis reproduced under licence and remains the intellectualproperty of Cambridge Assessment International Education.HarperCollinsPublishers Limited 2020Exam-style questions have been written by the authors.In examinations,the way marks are awarded may be different.10987654321References to assessment and/or assessment preparation are thepublisher's interpretation of the syllabus requirements and mayISBN978-0-00-833372-0not fully reflect the approach of Cambridge AssessmentInternational Education.All rights reserved.Except where indicated,no part of thispublication may be reproduced,stored in a retrieval system,orCambridge International recommends that teachers considertransmitted in any form by any means,electronic,mechanical,using a range of teaching and learning resources in preparingphotocopying,recording or otherwise,without the priorlearners for assessment,based on their own professionalwritten permission of the Publisher or a licence permittingjudgement of their students'needs.restricted copying in the United Kingdom issued by theCopyright Licensing Agency Ltd,Barnard's Inn,86 Fetter Lane,The publishers gratefully acknowledge the permission grantedLondon,EC4A IEN.to reproduce the copyright material in this book.Every efforthas been made to trace copyright holders and to obtain theirBritish Library Cataloguing-in-Publication Datapermission for the use of copyright material.The publishers willgladly receive any information enabling them to rectify anyA catalogue record for this publication is available from theerror or omission at the first opportunity.British Library.Authors:Michael Smyth,Lynn Pharaoh,Richard Grimmer,Chris Bishop,Carol DavenportPublisher:Elaine HiggletonProduct manager:Joanna RamsayContent editor:Tina PietronProject manager:Susan LyonsDevelopment editors:Gillian Lindsey,Jane RothCopyeditor:Jim NewallTypesetter,illustrator and indexer:Jouve India Private LtdProofreader:Jeremy PollardArtwork permissions researcher:Rachel ThorneMaps created or checked by Collins Bartholomew Ltd 2019Cover designer:Gordon MacGilpCover illustration:Ann PaganuzziProduction controller:Lyndsey RogersPrinted in Italy by Grafica Veneta S.p.A.With thanks to David Styles for his help on this project.