Synopses & Reviews
LABORATORY MANUAL IN PHYSICS BY A. A. KNOWLTON, PH. D. Professor of Physics, Reed College AND MARCUS ODAY, PH. D. Assistant Professor of Physics, Reed College SECOND EDITION McGRAW-HILL BOOK COMPANY, INC. NEW YORK AND LONDON 1935 COPYRIGHT, 1930, 1935, BY THE McGRAW-HiLL BOOK COMPANY, INC. PRINTED IN THE UNITED STATES OF AMERICA All rights reserved. This book, or parts thereof, may not be reproduced in any form without permission of the publishers. THE MAPLE PRESS COMPANY, YORK, PA. PREFACE TO THE SECOND EDITION With the exception of Exercises 11, 12a 26, 27, and 51 the material is identical with that in the First Edition. The order of topics has been changed to agree with that in the Second Edition of Physics for College Students and all page and chapter references have been corrected to refer to that edition. A. A. KNOWLTON. MARCUS ODAY. PORTLAND, ORE. September, 1935. PREFACE TO THE FIRST EDITION Why should students of general physics be required to do laboratory work This question is being rather persistently asked by the non-scientific members of college faculties and by administrators. Critics of the laboratory are likely to explain that they are interested in a set of conditions which will enable non-scientific students to get a broad general knowledge of the great principles and theories of physical science. This is certainly a reasonable desire and, if the laboratory does not contribute to this end, it will probably have to go, so far as such students are concerned. The recent popularity of courses about science usually designated as science survey courses is an illustration of the modern trend. Physics has an unenviable reputation for difficulty. This difficulty is oftencharged to mathematics whatever that may mean. An analysis of student troubles seems to the authors to indicate that the difficulties are, in a great majority of cases, due to the multitude of new concepts abstract ideas to which the student of general physics is unavoidably introduced at the very outset. As an illustration consider the following problems a. A housekeeper buys 8 pounds of sausage at 25 cents per pound and 8 pounds of potatoes which sell at the rate of 32 pounds for a dollar. What is the total cost b. A box weighing 8 pounds is moved along a rough floor, the coefficient of friction being 0.25, and is at the same time accelerated 1 ft. sec. 2 What force in pounds is required The solutions may be written out as follows a. Cost of sausage - f cost of potatoes total cost. 8 X 0.25 - - 2.25 6. Force to overcome friction force to accelerate total force. 8 X 0.25 j 2.25 Ib. The reasoning and the arithmetical work involved in the two solutions are identical but the second problem deals with PREFACE TO THE FIRST EDITION vii unfamiliar ideas and is, for that reason, far more difficult. And the difficulty cannot be avoided. The fundamental concepts of physics forcd, acceleration, etc. must become familiar to the student before he can acquire that broad general knowledge of physical principles and theories which the critics of the labora tory method desire. This necessity is as inescapable as the need for the acquisition of a French vocabulary and some knowledge of the technique grammar of the French language if one wishes to read the works of Anatole France in the original. There is another point of importance about physical concepts. They are new in kind as well as newindividually. For the most part they are quantitative, or perhaps it is better to say metric, in character that is, the concept is defined by the method used in measuring the thing defined. Herein lie the necessity and the justification for quantitative laboratory work...