The Elements of Astronomy, Physical and Geometrical: Done Into English, with Additions and Corrections. To which is Annex'd Dr. Halley's Synopsis of the Astronomy of CometsJ. Nicholson, 1715 - 441 oldal |
Gyakori szavak és kifejezések
accelerative Aftronomy alfo alſo Altitude angle Apfides Aphelion appear arifing Axis becauſe befides Body cafe caufe Celeſtial Centripetal Force Circle Circles of Latitude confequently defcribe demonftrated Diameter difference diſtance Diurnal Motion drawn Eaft Earth Ecliptic Ellipfe equal Equator faid fame manner fecond feems feen fhewn fide fince firft firſt fituation Fix'd Stars Focus fome fometimes ftance fuch fuppofed given Globe Gravity greater Axe greateſt Horizon Hour inferior Planet interfection intire itſelf Jupiter Latitude leffer lefs likewife Longitude magnitude mean Anomaly meaſure Meridian moft Moon moved namely Node obferved oppofite Orbit Parallax parallel perpendicular Phænomena Phænomenon Phyfical pofition Pole preced Primary Planets Prop PROPOSITION ratio reafon reciprocally refpect reft revolving Rifing Right Afcenfion right line Saturn SCHOLIUM Sine ſpace Sphere Squares Sun's Syftem thefe themſelves theſe thofe thoſe tis evident Triangle true Anomaly uſed Venus Vortex Weft whofe
Népszerű szakaszok
120. oldal - ... the squares of the periodic times are as the cubes of the distances from the common centre, the centripetal forces will be inversely as the squares of the distances.
229. oldal - Month, is the i ath of the fame according to the New. As the Form of the Year in different Nations is various, fo alfo is the Beginning of it.
61. oldal - If a body revolves in an ellipse (including the special case of a circle), it is required to find the law of the centripetal force tending to the focus of the ellipse.
119. oldal - Let us now go on to the other planets. Because the revolutions of the primary planets about the sun and of the secondary about Jupiter and Saturn are phenomena of the same kind with the revolution of the moon about the earth, and because it has been moreover demonstrated that the centripetal forces of the primary planets are directed towards the centre of the sun and those of the secondary towards the centres of Jupiter and...
v. oldal - ... therefore prefer the latter, taking account of its variation by the effect of precession, and restoring it, by calculation at every instant, to a fixed position. Now, to determine the situation of the ellipse described by a planet with respect to this plane, three elements require to be known : — 1st, the inclination of the plane of the planet's orbit to the plane of the ecliptic ; 2dly, the line in which these two planes intersect each other, which of necessity passes through the sun, and...
34. oldal - COR. 1. Therefore, since those arcs are as the velocities of the bodies, the centripetal forces are in a ratio compounded of the duplicate ratio of the velocities directly, and of the simple ratio of the radii inversely. COR. 2. And since the periodic times are in a ratio compounded of the ratio of the radii directly and the ratio of the velocities inversely, the centripetal forces are in a ratio compounded of the ratio of the radii directly and the...
25. oldal - ... of forces. PROPOSITION III. THEOREM III. Every body, that by a radius drawn to the centre of another body, howsoever moved, describes areas about that centre proportional to the times, is urged by a force compounded of the centripetal force tending to that other body, and of all the accelerative force by which that other body is impelled.
iv. oldal - ... between 16° and 1°. 2976. Line of nodes. — The inclination is not enough to determine the position of the plane of the orbit, for it is evident that an infinite variety of different planes may be inclined at the same angle to the ecliptic. If, however, the direction of the line of intersection of the plane of the orbit with the plane of the ecliptic (which line must always pass through the centre of the sun) be also defined, the position of the plane of the orbit will be determined. This...