6672 THE CAMBRIDGE COURSE OF ELEMENTARY NATURAL PHILOSOPHY: BEING THE PROPOSITIONS IN MECHANICS AND HYDROSTATICS IN WHICH THOSE PERSONS WHO ARE NOT CANDIDATES FOR HONOURS ARE FIFTH EDITION, REVISED AND ENLARGED, BY THOMAS LUND, B.D. LATE FELLOW AND LECTURER OF ST. JOHN'S COLLEGE, Cambridge and London. MACMILLAN AND CO. 1864. MECHANICS. [The explanatory matter, printed in small type, forms no actual part of the UNIVERSITY COURSE ; but is illustrative of the particular Definition, or Proposition, which it immediately follows; and will be found useful for answering the Questions, and solving the Problems, which are usually given in the University Examinations.] CHAPTER I. DEFINITIONS; EXPLANATION OF STATICAL FORCES; THE MANNER IN WHICH THEY ARE MEASURED, AND REPRESENTED. 1. MECHANICS is the science, which treats of the causes that prevent, or produce, motion in bodies, or that tend to prevent, or produce, motion. It is divided into two parts. The one, which investigates the conditions fulfilled when a body is in a state of rest, is called STATICS. The other, which treats of the causes and the effects of motion, is called DYNAMICS. Thus it is the province of STATICS to shew how the roof of a building is supported by the beams and the walls. If the roof gave way, and fell, it would belong to DYNAMICS to account for the circumstances attending the fall-to explain why the motion took place in one direction rather than in another-to determine the time elapsed in falling-and the swiftness of the motion at any instant. The part of MECHANICS treated on in the following pages is STATICS. L. C. C. 1 |