Philosophiæ naturalis principia mathematica autore Js. Newton ...

About this Item

Title
Philosophiæ naturalis principia mathematica autore Js. Newton ...
Author
Newton, Isaac, Sir, 1642-1727.
Publication
Londini :: Jussu Societatis Regiae ac Typis Josephi Streater ...,
1687.
Rights/Permissions

To the extent possible under law, the Text Creation Partnership has waived all copyright and related or neighboring rights to this keyboarded and encoded edition of the work described above, according to the terms of the CC0 1.0 Public Domain Dedication (http://creativecommons.org/publicdomain/zero/1.0/). This waiver does not extend to any page images or other supplementary files associated with this work, which may be protected by copyright or other license restrictions. Please go to http://www.textcreationpartnership.org/ for more information.

Subject terms
Mechanics -- Early works to 1800.
Celestial mechanics -- Early works to 1800.
Link to this Item
http://name.umdl.umich.edu/A52251.0001.001
Cite this Item
"Philosophiæ naturalis principia mathematica autore Js. Newton ..." In the digital collection Early English Books Online. https://name.umdl.umich.edu/A52251.0001.001. University of Michigan Library Digital Collections. Accessed June 10, 2024.

Pages

Prop. XXII. Prob. XIV.
Trajectoriam per data quin{que} puncta describere.

Dentur puncta quin{que} A, B, C, D, P. Ab eorum aliquo A ad alia duo quaevis B, C, quae poli nominentur, age rectas AB, AC his{que} parallelas TPS,

[illustration]
PRQ per punctum quartum P. Dein∣de a polis duobus B, C age per punc∣tum quintum D in∣finitas duas BDT, CRD, novissime duc∣tis TPS, PRQ (priorem priori & posteriorem posteri∣ori) occurentes in T & R. Deni{que} de rectis PT, PR, acta recta tr ipsi TR parallela, abscinde quas∣vis

Page 80

Pt, Pr ipsis PT, PR proportionales, & si per earum termi∣nos t, r & polos B, C actae Bt, Cr concurrant in d, locabitur punctum illud d in

[illustration]
Trajectoria quaesita. Nam punctum illud d (per Lem. XX) versatur in Conica Sectione per puncta quatuor A, B, P, C transeunte; & line∣is Rr, Tt evanescen∣tibus, coit punctum d cum puncto D. Transit ergo sectio Conica per puncta quin{que} A, B C, D, P. Q.E.D.

Idem aliter.

E punctis datis jun∣ge

[illustration]
tria quaevis A, B, C, & circum duo eorum B, C ceu polos, ro∣tando angulos magni∣tudine datos ABC, ACB, applicentur cru∣ra BA, CA primo ad punctum D, deinde ad punctum P, & no∣tentur puncta M, N in quibus altera crura BL, CL casu utro{que} se decussant. Agatur recta insinita MN, & rotentur anguli illi mobiles circum polos suos B, C, ea lege ut

Page 81

crurum BA, CA, vel BD, CD intersectio, quae jam sit d, Tra∣jectoriam quaesitam PADdB delineabit. Nam punctum d per Lem. XXI continget sectionem Conicam per puncta B, C trans∣euntem & ubi punctum m accedit ad puncta L, M, N, punctum d (per constructionem) accedet ad puncta A, D, P. Describetur ita{que} sectio Conica transiens per puncta quin{que} A, B, C, D, P. Q.E.F.

Corol. 1. Hinc rectae expedite duci possunt quae trajectoriam in punctis quibusvis datis B, C tangent. In casu utrovis accedat punctum d ad punctum C & recta Cd evadet tangens quaesita.

Corol. 2. Unde etiam Trajectoriarum centra, diametri & la∣tera recta inveniri possunt, ut in Corollario secundo Lemmatis XIX

Schol.

Constructio in casu priore evadet paulo simplicior jungendo BP, & in ea si opus est producta, capiendo Bp ad BP ut est PR ad PT, & per p agendo rectam insinitam pD ipsi SPT pa∣rallelam, in{que} ea capiendo semper pD aequalem Pr, & agendo rectas BD, Cr concurrentes in d. Nam cum sint Pr ad Pt, PR ad PT, pB ad PB, pD ad Pt in eadem ratione, erunt pD & Pr semper aequales. Hac methodo puncta Trajectoriae inveni∣untur expeditissime, nisi mavis Curvam, ut in casu secundo, de∣scribere Mechanice.

Do you have questions about this content? Need to report a problem? Please contact us.