Physical Science [antikvár]

PREFACE During the past several years great changes have been made in the science courses offered at the senior high school level. The biology, chemistry, and physics courses of today bear little resemblance to those of only a decade ago. Intellectual sights have been raised. The purpose and goals of introductory courses in these three sciences—and, indeed, in all the sciences—have been reexamined. The methods of teaching science have been drastically revised. And the content of the different courses has been changed accordingly. At the same time increased attention has been given to the teaching of science at the elementary level, so that the average student reaching the seventh grade today has a far greater knowledge of science and a better understanding of its methods than his predecessors of only a few years ago. These developments have prompted a parallel reexamination and réévaluation of the junior high school science program. What science should be taught? How should the courses be organized to fit into the pattern already established for the higher grades? Numerous groups of educators have wrestled with these questions, and a number of different answers have been proposed. One solution that has attracted considerable support and seems to be proving successful is to offer subject-oriented courses in life science, earth science and physical science in the junior high school grades. Physical science, of course, is not new to the junior high school curriculum. Courses have been taught with that title for some years. Such courses, however, almost invariably included units on geology, astronomy and meteorology, areas included in the earth science course. For that reason, and more significantiy because the developments in the senior high school science curriculum have imposed new requirements on the junior high school program, many science teachers believe that the physical science course should concern itself with and confine itself to an exploration of the fundamentals of physics and chemistry. It is to meet the recommendations of these teachers that this textbook has been written. In doing so it departs radically from the organization and subject matter of the earlier physical science— a basic course from which it stems and which it is designed to replace. The authors' purpose, however, is the same—to prepare students for further study in the physical sciences if they are so inclined and to enable those for whom this will be a terminal course in the physical sciences to cope most effectively with everyday problems in this scientific age. physical science—a modern approach begins and ends with a discussion of rockets and space travel: The one a discursive description of rocket flight; the other a more comprehensive treatment of the scientific principles involved. Between the beginning and the end the scientific picture is developed naturally. That is to say, science is not presented as an