Newton's principia, first book sections I, II, III, with notes and illustrations and a collection of problems, principally intended as examples of Newton's methods (1900)
each case, the body may be supposed for ashort time to be moving in the circle of curvature,and the forces are the same as those which wouldretain the body in the circular orbit; therefore,since the areas described in a given time are equal,the ratio of the forces is EP\SP : Sa\ Observations on the… … 8 is exterior to the circle^ in which case the force is repulsivethrough the arc BG, which is convex to the centre offeree, andcontained between the tangents drawn from ^S to the circle. It is important, however, to observe that this problem is tofind what would be the law of force tending to S,…
Mechanics · Celestial mechanics
Internet Archive · Boston Library Consortium · Public Domain Mark 1.0. Free to use for anything.
