239:
860:
477:
2568:
387:
214:. Given the speed at which such a fall would occur, it is doubtful that Galileo could have extracted much information from this experiment. Most of his observations of falling bodies were really of bodies rolling down ramps. This slowed things down enough to the point where he was able to measure the time intervals with
1371:
density cannot be assumed to be constant, such as for objects falling from high altitude, the equation of motion becomes much more difficult to solve analytically and a numerical simulation of the motion is usually necessary. The figure shows the forces acting on meteoroids falling through the Earth's upper atmosphere.
1598:
472:
This is the "textbook" case of the vertical motion of an object falling a small distance close to the surface of a planet. It is a good approximation in air as long as the force of gravity on the object is much greater than the force of air resistance, or equivalently the object's velocity is always
1391:
It can be said that two objects in space orbiting each other in the absence of other forces are in free fall around each other, e.g. that the Moon or an artificial satellite "falls around" the Earth, or a planet "falls around" the Sun. Assuming spherical objects means that the equation of motion is
444:
on August 2, 1971. He simultaneously released a hammer and a feather from the same height above the Moon's surface. The hammer and the feather both fell at the same rate and hit the surface at the same time. This demonstrated
Galileo's discovery that, in the absence of air resistance, all objects
148:
In the
Western world prior to the 16th century, it was generally assumed that the speed of a falling body would be proportional to its weightāthat is, a 10 kg object was expected to fall ten times faster than an otherwise identical 1 kg object through the same medium. The ancient Greek
1370:
Using the figure of 56 m/s for the terminal velocity of a human, one finds that after 10 seconds he will have fallen 348 metres and attained 94% of terminal velocity, and after 12 seconds he will have fallen 455 metres and will have attained 97% of terminal velocity. However, when the air
2368:
437:, and relative surface area and will only be achieved if the fall is from sufficient altitude. A typical skydiver in a spread-eagle position will reach terminal velocity after about 12 seconds, during which time they will have fallen around 450 m (1,500 ft).
433:. With air resistance acting on an object that has been dropped, the object will eventually reach a terminal velocity, which is around 53 m/s (190 km/h or 118 mph) for a human skydiver. The terminal velocity depends on many factors including mass,
2739:
The experimental observation that all objects in free fall accelerate at the same rate, as noted by
Galileo and then embodied in Newton's theory as the equality of gravitational and inertial masses, and later confirmed to high accuracy by modern forms of the
322:
Technically, an object is in free fall even when moving upwards or instantaneously at rest at the top of its motion. If gravity is the only influence acting, then the acceleration is always downward and has the same magnitude for all bodies, commonly denoted
218:
and his own pulse (stopwatches having not yet been invented). He repeated this "a full hundred times" until he had achieved "an accuracy such that the deviation between two observations never exceeded one-tenth of a pulse beat." In 1589ā1592, Galileo wrote
1030:
1985:
1365:
1443:
1177:
2563:{\displaystyle y(t)=y_{0}\left(x-{\frac {1}{5}}x^{2}-{\frac {3}{175}}x^{3}-{\frac {23}{7875}}x^{4}-{\frac {1894}{3031875}}x^{5}-{\frac {3293}{21896875}}x^{6}-{\frac {2418092}{62077640625}}x^{7}-\cdots \right)\ ,}
1256:
1866:
2357:
621:
2082:
2029:
1751:
1086:
534:
2693:
937:
423:
1877:
1267:
1593:{\displaystyle t(y)={\sqrt {\frac {{y_{0}}^{3}}{2\mu }}}\left({\sqrt {{\frac {y}{y_{0}}}\left(1-{\frac {y}{y_{0}}}\right)}}+\arccos {\sqrt {\frac {y}{y_{0}}}}\right),}
738:
655:
770:
687:
1675:
1053:
371:
Descending to the Earth using a parachute, which balances the force of gravity with an aerodynamic drag force (and with some parachutes, an additional lift force).
1785:
837:
814:
791:
708:
61:. An object moving upwards might not normally be considered to be falling, but if it is subject to only the force of gravity, it is said to be in free fall. The
1695:
1646:
1624:
929:
905:
885:
341:
211:
205:
186:, al-BaghdÄdÄ«'s theory of motion was "the oldest negation of Aristotle's fundamental dynamic law , anticipation in a vague fashion of the fundamental law of
2716:
is flat, the
Newtonian theory of free fall agrees with general relativity. Otherwise the two disagree; e.g., only general relativity can account for the
375:
The example of a falling skydiver who has not yet deployed a parachute is not considered free fall from a physics perspective, since they experience a
851:, the distance fallen in successive time intervals grows as the odd numbers. This description of the behavior of falling bodies was given by Galileo.
1393:
1101:
847:
If the initial velocity is zero, then the distance fallen from the initial position will grow as the square of the elapsed time. Moreover, because
318:
An object thrown upward or a person jumping off the ground at low speed (i.e. as long as air resistance is negligible in comparison to weight).
2910:
175:
2040:
1405:
1192:
390:
Measured fall time of a small steel sphere falling from various heights. The data is in good agreement with the predicted fall time of
2819:
2767:
1372:
1796:
2828:
2093:
429:
Near the surface of the Earth, an object in free fall in a vacuum will accelerate at approximately 9.8 m/s, independent of its
282:
249:
1754:
1408:. This connection between falling objects close to the Earth and orbiting objects is best illustrated by the thought experiment,
119:
drag forces in such situations prevent them from producing full weightlessness, and thus a skydiver's "free fall" after reaching
171:
challenged this argument and said that, by observation, two balls of very different weights will fall at nearly the same speed.
2709:
143:
1397:
542:
1437:
for two point objects on a radial path. The solution of this equation of motion yields time as a function of separation:
2757:
911:
well above the critical
Reynolds number, so that the air resistance is proportional to the square of the fall velocity,
100:, a condition that also occurs when the gravitational field is weak (such as when far away from any source of gravity).
264:
1430:
446:
179:
31:
260:
103:
The term "free fall" is often used more loosely than in the strict sense defined above. Thus, falling through an
1261:
The object's speed versus time can be integrated over time to find the vertical position as a function of time:
2772:
2741:
2708:
In general relativity, an object in free fall is subject to no force and is an inertial body moving along a
2045:
346:
Since all objects fall at the same rate in the absence of other forces, objects and people will experience
1409:
1993:
1701:
2745:
88:
gravity acts on each part of a body approximately equally. When there are no other forces, such as the
1025:{\displaystyle m{\frac {\mathrm {d} v}{\mathrm {d} t}}=mg-{\frac {1}{2}}\rho C_{\mathrm {D} }Av^{2}\,,}
1062:
863:
Acceleration of a small meteoroid when entering the Earth's atmosphere at different initial velocities
3091:
3039:
2992:
2943:
2857:
1980:{\displaystyle y(t)=y_{0}~Q\left(1-{\frac {t}{t_{\text{ff}}}};{\frac {3}{2}},{\frac {1}{2}}\right)~,}
1420:
1360:{\displaystyle y=y_{0}-{\frac {v_{\infty }^{2}}{g}}\ln \cosh \left({\frac {gt}{v_{\infty }}}\right).}
487:
164:
2578:
393:
2729:
2725:
462:
187:
155:
85:
38:
1095:
Assuming an object falling from rest and no change in air density with altitude, the solution is:
3057:
2982:
2703:
221:
131:
127:
58:
3120:
78:
3008:
2906:
2824:
2777:
2032:
1380:
380:
120:
74:
2900:
715:
632:
3146:
3141:
3099:
3047:
3000:
2951:
2036:
1416:
1089:
745:
662:
434:
1653:
1038:
304:(in space) with propulsion off (e.g. in a continuous orbit, or on a suborbital trajectory (
1401:
908:
199:
168:
46:
2928:
1764:
821:
798:
775:
692:
3095:
3043:
2996:
2947:
476:
2971:"From Cavitation to Astrophysics: Explicit Solution of the Spherical Collapse Equation"
2970:
2782:
2733:
1788:
1680:
1631:
1609:
1434:
1183:
1056:
914:
890:
870:
347:
326:
97:
3135:
3061:
3052:
3027:
2721:
1376:
848:
70:
2874:
1092:, assumed to be constant although in general it will depend on the Reynolds number.
365:
358:
183:
89:
57:
acting upon it. A freely falling object may not necessarily be falling down in the
2840:
Abel B. Franco (October 2003). "Avempace, Projectile Motion, and
Impetus Theory",
123:
produces the sensation of the body's weight being supported on a cushion of air.
3004:
441:
215:
116:
3076:
2748:, from which basis Einstein's theory of general relativity initially took off.
2717:
376:
305:
301:
104:
1172:{\displaystyle v(t)=v_{\infty }\tanh \left({\frac {gt}{v_{\infty }}}\right),}
2713:
859:
312:
160:
150:
108:
93:
3012:
2087:
This solution can also be represented exactly by the analytic power series
445:
experience the same acceleration due to gravity. On the Moon, however, the
425:, where h is the height and g is the free-fall acceleration due to gravity.
96:
in orbit) and its surrounding objects, it will result in the sensation of
3125:
867:
This case, which applies to skydivers, parachutists or any body of mass,
17:
2762:
840:
364:
Standing on the ground: the gravitational force is counteracted by the
50:
3103:
386:
1415:
The motion of two objects moving radially towards each other with no
2955:
267:. Statements consisting only of original research should be removed.
2987:
2899:
Olenick, Richard P.; Apostol, Tom M.; Goodstein, David L. (2008).
2823:. Vol. 1. New York: Charles Scribner's Sons. pp. 26ā28.
1871:
The separation can be expressed explicitly as a function of time
858:
385:
212:
dropped two objects of unequal mass from the
Leaning Tower of Pisa
66:
54:
2817:
Pines, Shlomo (1970). "Abu'l-BarakÄt al-BaghdÄdÄ« , Hibat Allah".
1251:{\displaystyle v_{\infty }={\sqrt {\frac {2mg}{\rho C_{D}A}}}\,.}
210:
According to a tale that may be apocryphal, in 1589ā1592 Galileo
430:
62:
1861:{\displaystyle t_{\text{ff}}=\pi {\sqrt {y_{0}^{3}/(8\mu )}}~.}
2837:
2352:{\displaystyle y(t)=\sum _{n=1}^{\infty }\left\right)\right].}
232:
225:, an unpublished manuscript on the motion of falling bodies.
475:
357:
Flying in an aircraft: there is also an additional force of
2902:
The
Mechanical Universe: Introduction to Mechanics and Heat
2712:. Far away from any sources of space-time curvature, where
1419:
can be considered a special case of an elliptical orbit of
657:
is the initial vertical component of the velocity (m/s).
2806:. Cambridge, MA: Harvard University Press. p. 220.
256:
2858:"The Feynman Lectures on Physics Vol. I Ch. 8: Motion"
616:{\displaystyle y(t)=v_{0}t+y_{0}-{\frac {1}{2}}gt^{2}}
3028:"From Moon-fall to motions under inverse square laws"
2581:
2371:
2096:
2048:
1996:
1880:
1799:
1767:
1704:
1683:
1656:
1634:
1612:
1446:
1270:
1195:
1104:
1065:
1041:
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917:
893:
873:
824:
801:
778:
748:
718:
695:
665:
635:
545:
490:
396:
329:
3077:"Radial Motion of Two Mutually Attracting Particles"
440:
Free fall was demonstrated on the Moon by astronaut
2687:
2562:
2351:
2076:
2023:
1979:
1860:
1779:
1745:
1689:
1669:
1640:
1618:
1592:
1359:
1250:
1171:
1080:
1047:
1024:
923:
899:
879:
831:
808:
785:
764:
732:
702:
681:
649:
615:
528:
473:much less than the terminal velocity (see below).
468:Uniform gravitational field without air resistance
417:
335:
111:, or lifting device, is also often referred to as
1648:is the distance between the centers of the bodies
379:that equals their weight once they have achieved
134:, a body in free fall has no force acting on it.
2139:
2802:Cohen, Morris R.; Drabkin, I. E., eds. (1958).
1383:'s record jumps, also belong in this category.
855:Uniform gravitational field with air resistance
449:is approximately 1.63 m/s, or only about ā
2869:
2867:
689:is the vertical component of the velocity at
8:
308:) going up for some minutes, and then down).
2905:. Cambridge University Press. p. 18.
849:the odd numbers sum to the perfect squares
296:Examples of objects in free fall include:
206:Galileo's Leaning Tower of Pisa experiment
153:(384ā322 BC) discussed falling objects in
3051:
2986:
2672:
2668:
2649:
2642:
2637:
2625:
2609:
2594:
2580:
2537:
2523:
2514:
2500:
2491:
2477:
2468:
2454:
2445:
2431:
2422:
2408:
2391:
2370:
2316:
2312:
2296:
2284:
2271:
2249:
2237:
2213:
2212:
2203:
2190:
2189:
2184:
2181:
2165:
2159:
2142:
2127:
2116:
2095:
2053:
2047:
1995:
1956:
1943:
1932:
1923:
1900:
1879:
1833:
1827:
1822:
1816:
1804:
1798:
1766:
1734:
1721:
1703:
1682:
1661:
1655:
1633:
1611:
1573:
1563:
1539:
1530:
1511:
1502:
1500:
1478:
1471:
1466:
1462:
1445:
1342:
1328:
1301:
1296:
1290:
1281:
1269:
1244:
1231:
1209:
1200:
1194:
1154:
1140:
1124:
1103:
1071:
1070:
1064:
1040:
1018:
1012:
998:
997:
980:
957:
947:
944:
939:
916:
892:
872:
843:(9.81 m/s near the surface of the earth).
828:
823:
805:
800:
782:
777:
761:
747:
729:
723:
717:
699:
694:
678:
664:
646:
640:
634:
607:
590:
581:
565:
544:
525:
510:
489:
405:
397:
395:
328:
283:Learn how and when to remove this message
27:Motion of a body subject only to gravity
2794:
2724:or inspiral of compact binaries due to
1626:is the time after the start of the fall
159:(Book VII), one of the oldest books on
2925:An analysis of such jumps is given in
1387:Inverse-square law gravitational field
353:Examples of objects not in free-fall:
2077:{\displaystyle I_{x}(\alpha ,\beta )}
1394:Newton's law of universal gravitation
200:Galileo Galilei Ā§ Falling bodies
7:
2041:regularized incomplete beta function
130:, where gravitation is reduced to a
2728:, and the relativity of direction (
2024:{\displaystyle Q(x;\alpha ,\beta )}
1746:{\displaystyle \mu =G(m_{1}+m_{2})}
2969:Obreschkow, Danail (7 June 2024).
2820:Dictionary of Scientific Biography
2768:High-altitude military parachuting
2204:
2185:
2128:
1433:). This allows one to compute the
1343:
1297:
1201:
1155:
1125:
1072:
999:
958:
948:
311:An object dropped at the top of a
25:
2880:. Green Harbor Publications. 2010
1406:Kepler's laws of planetary motion
167:). Although, in the 6th century,
2927:Mohazzabi, P.; Shea, J. (1996).
2031:is the quantile function of the
1755:standard gravitational parameter
1081:{\displaystyle C_{\mathrm {D} }}
457:Free fall in Newtonian mechanics
237:
182:of falling bodies. According to
92:exerted between a body (e.g. an
65:is thus in free fall around the
2842:Journal of the History of Ideas
529:{\displaystyle v(t)=v_{0}-gt\,}
144:History of gravitational theory
2804:A Source Book in Greek Science
2688:{\displaystyle x=\left^{2/3}.}
2381:
2375:
2304:
2278:
2268:
2259:
2146:
2106:
2100:
2071:
2059:
2018:
2000:
1890:
1884:
1847:
1838:
1740:
1714:
1456:
1450:
1398:gravitational two-body problem
1114:
1108:
758:
752:
675:
669:
555:
549:
500:
494:
418:{\displaystyle {\sqrt {2h/g}}}
1:
2758:Equations for a falling body
931:, has an equation of motion
887:, and cross-sectional area,
740:is the initial altitude (m).
178:gave an explanation for the
3121:Freefall formula calculator
3032:European Journal of Physics
3005:10.1103/PhysRevE.109.065102
2936:American Journal of Physics
839:is the acceleration due to
263:the claims made and adding
3163:
3053:10.1088/0143-0807/29/5/012
2701:
1431:radial elliptic trajectory
460:
447:gravitational acceleration
203:
197:
180:gravitational acceleration
141:
32:Free fall (disambiguation)
29:
2929:"High altitude free fall"
176:Abu'l-BarakÄt al-BaghdÄdÄ«
3075:Mungan, Carl E. (2009).
2773:Reduced-gravity aircraft
2362:Evaluating this yields:
1677:is the initial value of
1396:, with solutions to the
733:{\displaystyle y_{0}\,}
650:{\displaystyle v_{0}\,}
3128:an educational website
2744:, is the basis of the
2689:
2564:
2353:
2132:
2078:
2025:
1981:
1862:
1781:
1747:
1691:
1671:
1642:
1620:
1594:
1361:
1252:
1173:
1082:
1049:
1026:
925:
901:
881:
864:
833:
810:
787:
766:
765:{\displaystyle y(t)\,}
734:
704:
683:
682:{\displaystyle v(t)\,}
651:
617:
530:
481:
426:
419:
337:
174:In 12th-century Iraq,
2746:equivalence principle
2702:Further information:
2698:In general relativity
2690:
2565:
2354:
2112:
2079:
2026:
1982:
1863:
1782:
1748:
1692:
1672:
1670:{\displaystyle y_{0}}
1643:
1621:
1595:
1362:
1253:
1174:
1083:
1050:
1048:{\displaystyle \rho }
1027:
926:
902:
882:
862:
834:
811:
788:
767:
735:
705:
684:
652:
618:
531:
479:
420:
389:
350:in these situations.
338:
84:In a roughly uniform
2579:
2369:
2094:
2046:
2035:, also known as the
1994:
1878:
1797:
1765:
1702:
1681:
1654:
1632:
1610:
1444:
1268:
1193:
1102:
1063:
1039:
938:
915:
891:
871:
822:
816:is time elapsed (s).
799:
776:
746:
716:
693:
663:
633:
543:
488:
394:
327:
165:Aristotelian physics
132:space-time curvature
30:For other uses, see
3126:The Way Things Fall
3096:2009PhTea..47..502M
3084:The Physics Teacher
3044:2008EJPh...29..987F
3026:Foong, S K (2008).
2997:2024PhRvE.109f5102O
2948:1996AmJPh..64.1242M
2847:(4), pp. 521ā546 .)
2730:geodetic precession
2726:gravitational waves
1832:
1780:{\displaystyle y=0}
1410:Newton's cannonball
1306:
832:{\displaystyle g\,}
809:{\displaystyle t\,}
786:{\displaystyle t\,}
772:is the altitude at
703:{\displaystyle t\,}
463:Newtonian mechanics
188:classical mechanics
107:without a deployed
86:gravitational field
45:is any motion of a
39:classical mechanics
2704:General relativity
2685:
2560:
2349:
2153:
2074:
2021:
1977:
1858:
1818:
1777:
1743:
1687:
1667:
1638:
1616:
1590:
1357:
1292:
1248:
1169:
1078:
1045:
1022:
921:
897:
877:
865:
829:
806:
783:
762:
730:
700:
679:
647:
613:
526:
482:
427:
415:
333:
248:possibly contains
222:De Motu Antiquiora
128:general relativity
126:In the context of
59:vertical direction
3104:10.1119/1.3246467
2912:978-0-521-71592-8
2875:"Free fall graph"
2778:Terminal velocity
2742:Eƶtvƶs experiment
2656:
2655:
2617:
2602:
2556:
2531:
2508:
2485:
2462:
2439:
2416:
2324:
2302:
2276:
2257:
2226:
2179:
2138:
2033:Beta distribution
1973:
1964:
1951:
1938:
1935:
1908:
1854:
1850:
1807:
1690:{\displaystyle y}
1641:{\displaystyle y}
1619:{\displaystyle t}
1580:
1579:
1552:
1545:
1517:
1493:
1492:
1381:Felix Baumgartner
1348:
1310:
1242:
1241:
1160:
988:
966:
924:{\displaystyle v}
900:{\displaystyle A}
880:{\displaystyle m}
598:
413:
381:terminal velocity
336:{\displaystyle g}
293:
292:
285:
250:original research
121:terminal velocity
16:(Redirected from
3154:
3108:
3107:
3081:
3072:
3066:
3065:
3055:
3023:
3017:
3016:
2990:
2966:
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2814:
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2799:
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2667:
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2595:
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2188:
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2170:
2169:
2160:
2152:
2131:
2126:
2083:
2081:
2080:
2075:
2058:
2057:
2037:inverse function
2030:
2028:
2027:
2022:
1986:
1984:
1983:
1978:
1971:
1970:
1966:
1965:
1957:
1952:
1944:
1939:
1937:
1936:
1933:
1924:
1906:
1905:
1904:
1867:
1865:
1864:
1859:
1852:
1851:
1837:
1831:
1826:
1817:
1809:
1808:
1805:
1786:
1784:
1783:
1778:
1752:
1750:
1749:
1744:
1739:
1738:
1726:
1725:
1696:
1694:
1693:
1688:
1676:
1674:
1673:
1668:
1666:
1665:
1647:
1645:
1644:
1639:
1625:
1623:
1622:
1617:
1599:
1597:
1596:
1591:
1586:
1582:
1581:
1578:
1577:
1565:
1564:
1553:
1551:
1547:
1546:
1544:
1543:
1531:
1518:
1516:
1515:
1503:
1501:
1494:
1491:
1483:
1482:
1477:
1476:
1475:
1464:
1463:
1428:
1417:angular momentum
1366:
1364:
1363:
1358:
1353:
1349:
1347:
1346:
1337:
1329:
1311:
1305:
1300:
1291:
1286:
1285:
1257:
1255:
1254:
1249:
1243:
1240:
1236:
1235:
1222:
1211:
1210:
1205:
1204:
1178:
1176:
1175:
1170:
1165:
1161:
1159:
1158:
1149:
1141:
1129:
1128:
1090:drag coefficient
1087:
1085:
1084:
1079:
1077:
1076:
1075:
1054:
1052:
1051:
1046:
1031:
1029:
1028:
1023:
1017:
1016:
1004:
1003:
1002:
989:
981:
967:
965:
961:
955:
951:
945:
930:
928:
927:
922:
906:
904:
903:
898:
886:
884:
883:
878:
838:
836:
835:
830:
815:
813:
812:
807:
792:
790:
789:
784:
771:
769:
768:
763:
739:
737:
736:
731:
728:
727:
709:
707:
706:
701:
688:
686:
685:
680:
656:
654:
653:
648:
645:
644:
622:
620:
619:
614:
612:
611:
599:
591:
586:
585:
570:
569:
535:
533:
532:
527:
515:
514:
435:drag coefficient
424:
422:
421:
416:
414:
409:
398:
368:from the ground.
342:
340:
339:
334:
288:
281:
277:
274:
268:
265:inline citations
241:
240:
233:
21:
3162:
3161:
3157:
3156:
3155:
3153:
3152:
3151:
3132:
3131:
3117:
3112:
3111:
3079:
3074:
3073:
3069:
3038:(5): 987ā1003.
3025:
3024:
3020:
2968:
2967:
2963:
2956:10.1119/1.18386
2931:
2926:
2924:
2920:
2913:
2898:
2897:
2893:
2883:
2881:
2877:
2873:
2872:
2865:
2856:
2855:
2851:
2835:
2831:
2816:
2815:
2811:
2801:
2800:
2796:
2791:
2754:
2720:of orbits, the
2706:
2700:
2638:
2636:
2628:
2608:
2604:
2593:
2589:
2588:
2577:
2576:
2533:
2510:
2487:
2464:
2441:
2418:
2401:
2397:
2387:
2367:
2366:
2292:
2248:
2244:
2243:
2233:
2232:
2228:
2208:
2202:
2183:
2171:
2161:
2158:
2154:
2137:
2133:
2092:
2091:
2049:
2044:
2043:
1992:
1991:
1928:
1916:
1912:
1896:
1876:
1875:
1800:
1795:
1794:
1763:
1762:
1730:
1717:
1700:
1699:
1679:
1678:
1657:
1652:
1651:
1630:
1629:
1608:
1607:
1569:
1535:
1523:
1519:
1507:
1499:
1495:
1484:
1467:
1465:
1442:
1441:
1423:
1402:elliptic orbits
1389:
1338:
1330:
1324:
1277:
1266:
1265:
1227:
1223:
1212:
1196:
1191:
1190:
1150:
1142:
1136:
1120:
1100:
1099:
1066:
1061:
1060:
1037:
1036:
1008:
993:
956:
946:
936:
935:
913:
912:
909:Reynolds number
889:
888:
869:
868:
857:
820:
819:
797:
796:
774:
773:
744:
743:
719:
714:
713:
691:
690:
661:
660:
636:
631:
630:
603:
577:
561:
541:
540:
506:
486:
485:
470:
465:
459:
453:that on Earth.
452:
392:
391:
325:
324:
295:
289:
278:
272:
269:
254:
242:
238:
231:
208:
202:
196:
194:Galileo Galilei
169:John Philoponus
146:
140:
79:Earth's surface
35:
28:
23:
22:
15:
12:
11:
5:
3160:
3158:
3150:
3149:
3144:
3134:
3133:
3130:
3129:
3123:
3116:
3115:External links
3113:
3110:
3109:
3090:(8): 502ā507.
3067:
3018:
2961:
2918:
2911:
2891:
2863:
2849:
2829:
2809:
2793:
2792:
2790:
2787:
2786:
2785:
2783:Weightlessness
2780:
2775:
2770:
2765:
2760:
2753:
2750:
2734:frame dragging
2699:
2696:
2684:
2679:
2675:
2671:
2666:
2661:
2652:
2645:
2641:
2634:
2631:
2624:
2621:
2616:
2613:
2607:
2601:
2598:
2592:
2587:
2584:
2571:
2570:
2559:
2552:
2548:
2545:
2540:
2536:
2530:
2527:
2522:
2517:
2513:
2507:
2504:
2499:
2494:
2490:
2484:
2481:
2476:
2471:
2467:
2461:
2458:
2453:
2448:
2444:
2438:
2435:
2430:
2425:
2421:
2415:
2412:
2407:
2404:
2400:
2394:
2390:
2386:
2383:
2380:
2377:
2374:
2360:
2359:
2348:
2344:
2339:
2334:
2328:
2323:
2320:
2315:
2310:
2306:
2299:
2295:
2291:
2288:
2283:
2280:
2275:
2270:
2267:
2264:
2261:
2256:
2253:
2247:
2240:
2236:
2231:
2222:
2219:
2216:
2211:
2206:
2199:
2196:
2193:
2187:
2177:
2174:
2168:
2164:
2157:
2151:
2148:
2145:
2141:
2136:
2130:
2125:
2122:
2119:
2115:
2111:
2108:
2105:
2102:
2099:
2073:
2070:
2067:
2064:
2061:
2056:
2052:
2020:
2017:
2014:
2011:
2008:
2005:
2002:
1999:
1988:
1987:
1976:
1969:
1963:
1960:
1955:
1950:
1947:
1942:
1931:
1927:
1922:
1919:
1915:
1911:
1903:
1899:
1895:
1892:
1889:
1886:
1883:
1869:
1868:
1857:
1849:
1846:
1843:
1840:
1836:
1830:
1825:
1821:
1815:
1812:
1803:
1789:free-fall time
1776:
1773:
1770:
1759:
1758:
1742:
1737:
1733:
1729:
1724:
1720:
1716:
1713:
1710:
1707:
1697:
1686:
1664:
1660:
1649:
1637:
1627:
1615:
1601:
1600:
1589:
1585:
1576:
1572:
1568:
1562:
1559:
1556:
1550:
1542:
1538:
1534:
1529:
1526:
1522:
1514:
1510:
1506:
1498:
1490:
1487:
1481:
1474:
1470:
1461:
1458:
1455:
1452:
1449:
1435:free-fall time
1388:
1385:
1368:
1367:
1356:
1352:
1345:
1341:
1336:
1333:
1327:
1323:
1320:
1317:
1314:
1309:
1304:
1299:
1295:
1289:
1284:
1280:
1276:
1273:
1259:
1258:
1247:
1239:
1234:
1230:
1226:
1221:
1218:
1215:
1208:
1203:
1199:
1184:terminal speed
1180:
1179:
1168:
1164:
1157:
1153:
1148:
1145:
1139:
1135:
1132:
1127:
1123:
1119:
1116:
1113:
1110:
1107:
1074:
1069:
1044:
1033:
1032:
1021:
1015:
1011:
1007:
1001:
996:
992:
987:
984:
979:
976:
973:
970:
964:
960:
954:
950:
943:
920:
896:
876:
856:
853:
845:
844:
827:
817:
804:
794:
781:
760:
757:
754:
751:
741:
726:
722:
711:
698:
677:
674:
671:
668:
658:
643:
639:
624:
623:
610:
606:
602:
597:
594:
589:
584:
580:
576:
573:
568:
564:
560:
557:
554:
551:
548:
537:
536:
524:
521:
518:
513:
509:
505:
502:
499:
496:
493:
469:
466:
461:Main article:
458:
455:
450:
412:
408:
404:
401:
373:
372:
369:
362:
348:weightlessness
332:
320:
319:
316:
309:
291:
290:
245:
243:
236:
230:
227:
195:
192:
142:Main article:
139:
136:
98:weightlessness
75:very far orbit
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
3159:
3148:
3145:
3143:
3140:
3139:
3137:
3127:
3124:
3122:
3119:
3118:
3114:
3105:
3101:
3097:
3093:
3089:
3085:
3078:
3071:
3068:
3063:
3059:
3054:
3049:
3045:
3041:
3037:
3033:
3029:
3022:
3019:
3014:
3010:
3006:
3002:
2998:
2994:
2989:
2984:
2981:(6): 065102.
2980:
2976:
2972:
2965:
2962:
2957:
2953:
2949:
2945:
2941:
2937:
2930:
2922:
2919:
2914:
2908:
2904:
2903:
2895:
2892:
2876:
2870:
2868:
2864:
2859:
2853:
2850:
2846:
2843:
2839:
2832:
2830:0-684-10114-9
2826:
2822:
2821:
2813:
2810:
2805:
2798:
2795:
2788:
2784:
2781:
2779:
2776:
2774:
2771:
2769:
2766:
2764:
2761:
2759:
2756:
2755:
2751:
2749:
2747:
2743:
2737:
2735:
2731:
2727:
2723:
2722:orbital decay
2719:
2715:
2711:
2705:
2697:
2695:
2682:
2677:
2673:
2669:
2664:
2659:
2650:
2643:
2639:
2632:
2629:
2622:
2619:
2614:
2611:
2605:
2599:
2596:
2590:
2585:
2582:
2574:
2557:
2550:
2546:
2543:
2538:
2534:
2528:
2525:
2520:
2515:
2511:
2505:
2502:
2497:
2492:
2488:
2482:
2479:
2474:
2469:
2465:
2459:
2456:
2451:
2446:
2442:
2436:
2433:
2428:
2423:
2419:
2413:
2410:
2405:
2402:
2398:
2392:
2388:
2384:
2378:
2372:
2365:
2364:
2363:
2346:
2342:
2337:
2332:
2326:
2321:
2318:
2313:
2308:
2297:
2293:
2289:
2286:
2281:
2273:
2265:
2262:
2254:
2251:
2245:
2238:
2234:
2229:
2220:
2217:
2214:
2209:
2197:
2194:
2191:
2175:
2172:
2166:
2162:
2155:
2149:
2143:
2134:
2123:
2120:
2117:
2113:
2109:
2103:
2097:
2090:
2089:
2088:
2085:
2068:
2065:
2062:
2054:
2050:
2042:
2038:
2034:
2015:
2012:
2009:
2006:
2003:
1997:
1974:
1967:
1961:
1958:
1953:
1948:
1945:
1940:
1929:
1925:
1920:
1917:
1913:
1909:
1901:
1897:
1893:
1887:
1881:
1874:
1873:
1872:
1855:
1844:
1841:
1834:
1828:
1823:
1819:
1813:
1810:
1801:
1793:
1792:
1791:
1790:
1774:
1771:
1768:
1761:Substituting
1756:
1735:
1731:
1727:
1722:
1718:
1711:
1708:
1705:
1698:
1684:
1662:
1658:
1650:
1635:
1628:
1613:
1606:
1605:
1604:
1587:
1583:
1574:
1570:
1566:
1560:
1557:
1554:
1548:
1540:
1536:
1532:
1527:
1524:
1520:
1512:
1508:
1504:
1496:
1488:
1485:
1479:
1472:
1468:
1459:
1453:
1447:
1440:
1439:
1438:
1436:
1432:
1426:
1422:
1418:
1413:
1411:
1407:
1403:
1399:
1395:
1386:
1384:
1382:
1378:
1377:Joe Kittinger
1374:
1354:
1350:
1339:
1334:
1331:
1325:
1321:
1318:
1315:
1312:
1307:
1302:
1293:
1287:
1282:
1278:
1274:
1271:
1264:
1263:
1262:
1245:
1237:
1232:
1228:
1224:
1219:
1216:
1213:
1206:
1197:
1189:
1188:
1187:
1185:
1166:
1162:
1151:
1146:
1143:
1137:
1133:
1130:
1121:
1117:
1111:
1105:
1098:
1097:
1096:
1093:
1091:
1067:
1058:
1042:
1019:
1013:
1009:
1005:
994:
990:
985:
982:
977:
974:
971:
968:
962:
952:
941:
934:
933:
932:
918:
910:
894:
874:
861:
854:
852:
850:
842:
825:
818:
802:
795:
779:
755:
749:
742:
724:
720:
712:
696:
672:
666:
659:
641:
637:
629:
628:
627:
608:
604:
600:
595:
592:
587:
582:
578:
574:
571:
566:
562:
558:
552:
546:
539:
538:
522:
519:
516:
511:
507:
503:
497:
491:
484:
483:
478:
474:
467:
464:
456:
454:
448:
443:
438:
436:
432:
410:
406:
402:
399:
388:
384:
383:(see below).
382:
378:
370:
367:
363:
360:
356:
355:
354:
351:
349:
344:
330:
317:
314:
310:
307:
303:
299:
298:
297:
287:
284:
276:
266:
262:
258:
252:
251:
246:This article
244:
235:
234:
228:
226:
224:
223:
217:
213:
207:
201:
193:
191:
189:
185:
181:
177:
172:
170:
166:
162:
158:
157:
152:
145:
137:
135:
133:
129:
124:
122:
118:
114:
110:
106:
101:
99:
95:
91:
87:
82:
80:
76:
72:
71:orbital speed
69:, though its
68:
64:
60:
56:
52:
48:
44:
40:
33:
19:
3087:
3083:
3070:
3035:
3031:
3021:
2978:
2975:Phys. Rev. E
2974:
2964:
2942:(10): 1242.
2939:
2935:
2921:
2901:
2894:
2882:. Retrieved
2852:
2844:
2841:
2818:
2812:
2803:
2797:
2738:
2707:
2575:
2572:
2361:
2086:
1989:
1870:
1760:
1602:
1424:
1421:eccentricity
1414:
1392:governed by
1390:
1375:, including
1369:
1260:
1186:is given by
1181:
1094:
1034:
866:
846:
625:
471:
439:
428:
374:
366:normal force
352:
345:
321:
294:
279:
270:
247:
220:
216:water clocks
209:
184:Shlomo Pines
173:
154:
149:philosopher
147:
125:
112:
102:
90:normal force
83:
73:keeps it in
53:is the only
42:
36:
2529:62077640625
1787:we get the
1057:air density
442:David Scott
117:aerodynamic
3136:Categories
2988:2401.05445
2789:References
2718:precession
1373:HALO jumps
1182:where the
377:drag force
306:ballistics
302:spacecraft
257:improve it
204:See also:
198:See also:
105:atmosphere
3062:122494969
2714:spacetime
2633:μ
2620:−
2612:π
2547:⋯
2544:−
2521:−
2498:−
2475:−
2452:−
2429:−
2406:−
2314:−
2290:−
2282:−
2266:
2218:−
2195:−
2147:→
2129:∞
2114:∑
2069:β
2063:α
2016:β
2010:α
1921:−
1845:μ
1814:π
1706:μ
1561:
1528:−
1489:μ
1344:∞
1322:
1316:
1298:∞
1288:−
1225:ρ
1202:∞
1156:∞
1134:
1126:∞
1043:ρ
991:ρ
978:−
588:−
517:−
480:Free-fall
313:drop tube
273:July 2020
261:verifying
161:mechanics
151:Aristotle
113:free fall
109:parachute
94:astronaut
77:from the
43:free fall
3013:39021019
2884:14 March
2752:See also
2710:geodesic
2506:21896875
1404:obeying
229:Examples
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3147:Gravity
3142:Falling
3092:Bibcode
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2993:Bibcode
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2763:G-force
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