Elements of Natural Philosophy Author:James Mitchell General Books publication date: 2009 Original publication date: 1819 Original Publisher: Printed for T. and J. Allman Subjects: Physics Science / Mathematical Physics Science / Physics Notes: This is a black and white OCR reprint of the original. It has no illustrations and there may be typos or missing text. When you buy the General ... more »Books edition of this book you get free trial access to Million-Books.com where you can select from more than a million books for free. Excerpt: OF MECHANICS. That branch of Natural Philosophy which treats of the motion of solid bodies it called Mechanics. Motion may be absolute or relative. Absolute motion is the change of place of a body to another place; thus, of a coach from this end of the street to the other. In such a case, a man in the coach, whilst he has absolute motion along with the coach, may be relatively at rest in regard to all the others in the coach. So, also, a man may sit still in a boat, and be relatively at rest in regard to all persons in the boat along with him, whilst he has an absolute motion from one side of the river to the other; but were the man to move from one part of the boat to another, he would, in regard to those about him, have a relative motion. Two ships carried along in a current at sea' for several miles, whilst they keep exactly in the same position in regard to each other, are relatively at rest. : , The laws by which all motion is regulated may be reduced to three. I. Every body continues in its state of rest or of uniform motion in a right line, unless compelled to change that state by force impressed. Let us examine the parts of this law separately. Every body continues in its state of rest. -- A stone on the ground will not leave its place, except some one remove it; even a leaf or a feather will not do so without some cause forcing it, as a gust of wind.3 It is so throughout all nature. If a bird hovering in the air were not drawn down it might continue for ever to do so. Th...« less