Practical Physics: Industrial Series

THE PENNSYLVANIA STATE COLLEGE INDUSTRIAL SERIES PRACTICAL PHYSICS The quality of the materials used in the manufacture cf this book is gov- erned by continued postwar shortages. THE PENNSYLVANIA STATE COLLEGE INDUSTRIAL SERIES BRENEMAN Mathematics, 2d ed. BRENEMAN Mechanics BRENEMAN Strength cf Materials SCHAEFER Job SCHAEFEU Instruction Safety Supervision SCHAEFER AND WlSSLER Industrial SupervisionOrganization SCHAEFER AND WISSLER Supervision THAYER Industrial Controls Blue Print Heading and Sketching THAYER Industrial Drawing WALTON Do You Want to Be a Foreman? WALTON The Fundamentals trial WHITE cf Indus- Psychology (Editor) Practical Physics INDUSTRIAL SERIES PRACTICAL PHYSICS BY MARSH W. WHITE, PH.D., Editor Professor of Physics KENNETH V. MANNING, PH.D. Assistarit Supervisor of Physics Exte7isio?i ROBERT L. WEBER, PH.D. Assistant, Professor of Physics R. ORIN CORNETT, PH.D. Lecturer in Electronics, Harvard University Formerly Assistant Supervisor of Physics Extension arid, others on THE PHYSICS EXTENSION STAFF The Pennsylvania State College FIRST EDITION EIGHTH IMPRESSION PREPARED UNDER THE DIRECTION OF THE DIVISION OF ARTS AND SCIENCE EXTENSION THE PENNSYLVANIA STATE COLLEGE McGRAW-HILL BOOK COMPANY, NEW YORK AND LONDON 1943 INC. PRACTICAL PHYSICS COPYRIGHT, 1943, BY THE PENNSYLVANIA STATE COLLEGE PRINTED IN THE UNITED STATES OF AMERICA All rights reserved. This book, or may not be reproduced parts thereofj in any form without permission of the publishers. THE MAPI ffi 1'BESS COMPANY, YORK, PA. FOREWORD In the and field of adult education the needs of the students are so varied their educational backgrounds are so diverse that conventional textbooks are often not satisfactory. To be most valuable for these groups the textbooks must be simple and practical, readily understand- by all and yet able to supplement experience at many levels. The Pennsylvania State College Industrial Series was originated in 1941 in an attempt to provide books having these desirable characteristics. able The earlier volumes of the were prepared by members of the staff This volume is the first contribution from series of the School of Engineering. the staff of the School of Chemistry and Physics. expected from the School of the Liberal Arts. Other books are The increased need for technically trained personnel has emphasized the shortage of persons with basic training in physics. To provide trainees with the minimum technical skill and knowledge of physical principles necessary for effective participation in war industries and in the armed services, short courses have been set up, covering only the For example, in extension classes of principles of most immediate use. the Engineering, Science and Management War Training Program, The Pennsylvania State College has given training in a course of basic mathematics and physics to more than 8,000 students in the period from 1941 to 1943. It was realized early that a new concise physics text was needed Consequently the present volume was prepared. " is designed to present in streamlined form the Practical Physics of general physics so that the