Knowledge

Talk:Second moment of area

Source 📝

1329:
required is an explanation of 2 independent relationships to radius. For example, in the case of rotational moment of inertia, I could explain how moment of inertia relates to torque and angular acceleration and then show that a particle of mass at radius r accelerates more as r is increased, and also how the moment of the accelerating force increases with r, thus giving an overall dependence on r^2. I would appreciate an analogous approach with 2nd moment of area, bending moment, and deflection (or condition of failure), or whatever the concepts are which are most relevant. Why is integral(r^2)da a significant metric; why is the square of the radius of an element of area important ? At present the underlying principles of the analysis remain obscure (to me at least). I think that the effective explanation of concepts in simple terms is a particular skill and needs more careful thought than is being used at present.
189: 74: 53: 179: 158: 84: 1208:
find it strange to talk about "bending of a plane". The plane is not bending. The plane is a section through a beam that is bending. One of the assumptions in the derivation of beam bending equations is that plane sections remain plane. That is, they don't bend. So I'm inclined to edit that sentence. I just haven't decided what I want it to say instead yet, so if anyone has any suggestions, I'd like to hear them.
22: 478: 553:
I added diagrams for the I-beam section. My lettering, which didn't look that bad in the original stands out now. I can redraw if there is interest. I could also add a variable for the the thickness of the top and bottom pieces. Before I do it, are there any other changes? (you can drop a comment
1720:
It's worth noticing here that there are two communities playing tug-of-war over this article: the math/physics people who keep saying that it is fundamentally wrong and the engineering-type folks who are trying to make it useful for us. The formulae that are here now match both the basic fundamental
1207:
The lead sentences says "This article is about the moment of inertia as related to the bending of a plane. For the moment of inertia dealing with rotation of an object, see Moment of inertia." I think it is great to distinguish the area moment of inertia from the mass moment of inertia. However, I
1228:
I agree, this article is terribly written to the point that it completely lost focus from what was supposed to be its subject. Whoever wrote it clearly had a limited grasp on the subject, and his limited understanding added to the confusion of mixing up the second moment of area with beam theory.
1116:
There is a discussion of mast calculations in here under the section on the second moment of area of a circular cross section. Everything the section mentions is true but are mast calculations really an important enough consideration to warrant a mention here? I think it adds unnecessary length to
1486:
I've reworked a lot of what was in the article to get rid of mentions to cross-section (still remnant of the beam-theory days). Also fixed some of the linkages. Added simple sections about parallel and perpendicular axis theorems and composite shapes. And removed the unnecessary example that just
1328:
As a non-expert I would like to know why the 'moment of inertia' of the cross-section of a beam is important in relation to stiffness or laibility to failure (Strength). I found the introduction of elastic stored energy unhelpful. Its relevance is not at all clear from what is written. What is
769:
What is this used for? Is it really related to the second moment because an object with both x-axis and y-axis symmetry would have a value of zero, whcih is certainly not true of the second moment (it more resembles a first moment). Can we clearify this before we put it back in teh article, if
1185:
I think it should be possible to define this concept mathematically, and then proceed to show how it is applied in various contexts, and notably for computation of bending stresses, with limitations and conditions. Perhaps the article should be renamed, and a new article about the specific
403:
As a Swede I find it strange that "area moment of inertia" is the last choice. In Swedish that is what we call it: "yttröghetsmoment". Compare to moment of inertia = sum up all the infinitesimal mass elements multiplied by the lever squared, versus area moment of inertia = sum up all the
1005: 1201:
As far as I know, beam bending analysis is the predominant (only?) use of second moment of area, so I think it's fine that the emphasis is on beam bending. I don't really care much about separating the pure math from the applied math. But I'm an engineer, not a
1161:
I think the bit that needed clarifying was that this a property of a cross section of body, not of a body. The area to include in the integral is simply the area of the cross section. Do you have any suggestions for further clarifications?
1011:
The trick is to find a coordinate system, which has a product moment of area equal to zero. This is always possible, and as you have noticed, it is trivial with a symmetric cross section. Then the bending formula becomes a lot simpler:
1095: 393:
The second moment of area is a more general concept. For example the static roll stability of a ship depends on the second moment of area of the waterline section - short fat ships are stable, long thin ones are not.
785: 1399:
I'd be interested to know for whom the article in its current state - with 'a symmetric tensor' in the third paragraph and 'Minimum total potential energy principle' in the fourth - is intended. You really
1377:
In the section "Product moment of area", the linked reference to "Pilkey 2002" does not seem to work, and I cannot find a book by that title or an book on a related subject by "Pilkey". Please clarify.
1490:
The only thing I have a question about is the product of inertia. Should this article include this? Or should we rewrite the existing page for product of inertia that just links here?
1808: 1309: 388: 765: 1140:
At each point with coordinates (x,y,z), there are infinitely many surfaces including that point, each with a different orientation. Which of them should be included in the sum?
1101:
The reason it has a redlink, is probably because all common cross sections have symmetry, and then there is no point in calculating it, so in real life it is only rarely used.
658: 1357:
I agree with everything above, but furthermore the second paragraph of 'Intuition' is not consistent with the first. Rewrite is needed: watch, as they don't say, that space!
1648:- Hey. I'm the user who edited it after you changed it. Honestly, I think I was looking at an older version of your series of edits, not the final one. What I saw reflected 1525:
So I changed some stuff in the Annulus section of the page. One thing to keep in mind (and I clarified this in a later edit) is that with that integral, I was calculating
140: 691: 1631: 1604: 1577: 1550: 780:
It is used in the bending formula, if for some reason you have a poor choice of coordinate system. The bending formula in the general form is relatively complicated:
1793: 1813: 245: 106: 465:'I' in the stress bending eqn should be for 2nd moment of area. I referred this from 'Mechanics of solids and structures', Benham, P.P. ISBN: 0273361910 588: 1493:
Also, I didn't remove the messages at the top. I would like someone else to review the article and clear them if they feel it's cleared up the issues.
1803: 235: 97: 58: 1248:
Something should be said about the product moment of area in this section. If I remember correctly, the formula used for that transformation is:
188: 1798: 1453: 1017: 274:
Spanish page refers the same Spanish book ... But I could not trust the formulae against the English one using symbolic computation (Sympy):
1788: 1468: 1358: 598: 130: 1000:{\displaystyle \sigma =-{\frac {M_{y}I_{x}+M_{x}I_{xy}}{I_{x}I_{y}-I_{xy}^{2}}}x+{\frac {M_{x}I_{y}+M_{y}I_{xy}}{I_{x}I_{y}-I_{xy}^{2}}}y} 1423:
I've cleaned up the article, which included a whole lot of nonsense and stuff which was simply wrong. The criteria for the cleanup was:
1163: 1405: 411: 211: 1698:
I have looked at the recent edits and can see major improvements, that result in a clarity of understanding. Keep up the Good Work!
1437:
This article is still a bit incomplete, but at least now it doesn't include blatant errors and misconceptions about its subject. --
1668: 1509: 288: 1783: 1721:
mathematics and principally the useage in engineering. I'd propose that the big warning at the top of the page be removed.
543:
A suitably dimensioned and annotated I-beam diagram would greatly enhance the usefulness and applicability of this forula.
498: 456: 202: 163: 1487:
pulls from the list. I only kept (and reorganized) examples that exploit some calculation of the second moment of area.
1136:
The cross sectional areas perpendicular to an axis, such that with a thickness, the volume of the body is accounted for?
513: 33: 1717:
I have read through the formulae and confirmed that all are correct (up to the polygons -- I didn't check that one.)
1345: 589:
http://www.dynamore.de/documents/papers/euro4/implicit-new-developments/ls-dyna-beam-elements-default-and-user-defined
494: 1765: 1684: 1638: 1146:
The definition lacks every hint of context. It is understandable only for those who already know what it means.
1457: 1606:. I think someone who edited it after me got confused about what I was calculating and changed some stuff to 1472: 1433:
examples must be exclusively about an area's geometric properties, because that's what any moment of area does
1362: 602: 21: 1404:
need to know about the Kronecker delta before you can form a working understanding of second moment of area.
1385: 1467:
If your work removed the blatant errors, etc, could you change the cleanup tag to reflect its current state?
1409: 1167: 612:
This material on the "product moment of area" was int eh article but seems to lack context and explanation:
441: 292: 1729: 1680: 1634: 694: 502: 415: 271:
Deutsch page has any reference and show a - sign for Ixy, which means there are wrong formulae on the web.
1664: 1505: 1381: 327: 313: 39: 1253: 344: 1660: 1501: 702: 73: 52: 1761: 1758:
Also, there are some explanations on how to deal with disconnected polygons and polygons with holes.
1725: 1703: 1699: 1656: 1497: 1333: 594: 407: 284: 618: 1442: 1314: 1234: 1117:
the article. I am cleaning the section up some but it needs to be considered for deletion anyway.
210:
on Knowledge. If you would like to participate, please visit the project page, where you can join
105:
on Knowledge. If you would like to participate, please visit the project page, where you can join
1652:
edit. My apologies for the confusion. I believe the article looks good. Thank you for the edit!
1217: 1191: 1151: 568: 395: 89: 1337: 591:
as an example of rectangular cross section beam. This was what made me understand the concept.
1182:
This page is not about second moment of area any more, it is about bending stress and strain.
452: 102: 666: 1609: 1582: 1555: 1528: 1341: 1102: 563:
Diagrams look good- however, they should have the coordinate system axis for completeness.
1750: 1438: 1230: 523:
This article needs some diagrams to go with the formulas, to make the variables clear.
194: 587:
I have found the math here too sloppy to be understandable. I suggest to put (7) from
83: 1777: 1452:
Why is that? It says right on this talk page that this is a Civil Engineering topic!
1213: 1187: 1147: 564: 448: 1769: 1733: 1707: 1688: 1672: 1642: 1513: 1476: 1461: 1445: 1413: 1389: 1366: 1349: 1318: 1237: 1221: 1195: 1171: 1155: 1105: 774: 606: 572: 558: 533: 460: 419: 398: 330: 324:
I think the second moment of area is different to the second moment of inertia.
316: 307:
The calculation of "y" the distance to the centroid is incorrect. It should be:
296: 178: 157: 1451:< if it mentioned any form of beam theory then it doesn't belong here. : --> 771: 555: 530: 184: 79: 1633:
if I recall correctly. I just wanted to justify why I switched it back. --
1125:
The definition does not state what areas are to be summed in the integral.
526:
Some body needs to translate and lift the diagrams from the De page on this
477: 1090:{\displaystyle \sigma =-{\frac {M_{y}}{I_{y}}}x+{\frac {M_{x}}{I_{x}}}y} 1430:
if it mentioned any form of stress then it has no place in this article
207: 1755:
I will program these equations and verify them against known results.
1427:
if it mentioned any form of beam theory then it doesn't belong here.
501:. Specific illustrations, plots or diagrams can be requested at the 278:
E1 = sympify('(yi**2 + yi*yi1 + yi1**2)*(xi * yi1 - xi1 * yi)')
430:
I had several problems with the changes made by 69.251.146.46:
472: 434:
The lead sentence shouldn't be about what it is confused with.
404:
infinitesimal area elements multiplied by the lever squared.
15: 1229:
This article needs a complete rewrite to stay meaningful. --
770:
this is where it belongs. And why does this have a redlink?
476: 1649: 1751:
https://apps.dtic.mil/dtic/tr/fulltext/u2/a183444.pdf
1612: 1585: 1558: 1531: 1256: 1020: 788: 705: 669: 621: 347: 206:, a collaborative effort to improve the coverage of 101:, a collaborative effort to improve the coverage of 1625: 1598: 1571: 1544: 1303: 1089: 999: 759: 685: 652: 382: 281:E2 = sympify('(xi1-xi)*(yi1+yi)*(yi1**2+yi**2)') 1724:I also tried to clean up some of the references. 1143:Can the sum include area elements that overlap? 1679:Ah I see. Thanks for the clarification! :) -- 1112:Why is there a discussion of mast calculations? 1809:Start-Class physics articles of Mid-importance 8: 267:This section must be checked by an expert. 19: 405: 282: 152: 47: 1617: 1611: 1590: 1584: 1563: 1557: 1536: 1530: 1280: 1261: 1255: 1076: 1066: 1060: 1046: 1036: 1030: 1019: 985: 977: 964: 954: 939: 929: 916: 906: 899: 884: 876: 863: 853: 838: 828: 815: 805: 798: 787: 704: 674: 668: 626: 620: 368: 352: 346: 154: 115:Knowledge:WikiProject Civil engineering 49: 1794:WikiProject Civil engineering articles 118:Template:WikiProject Civil engineering 7: 1814:Knowledge requested physics diagrams 1129:The elements of area comprising the 529:Comment moved from article to talk ( 200:This article is within the scope of 95:This article is within the scope of 1747:I found an appropriate reference. 38:It is of interest to the following 1304:{\displaystyle I_{xy}'=I_{xy}+Axy} 554:on the diagrams on my talk page.) 440:-- much less frequently used than 383:{\displaystyle I_{x}=\int y^{2}dm} 14: 1186:mathematical concept be written. 760:{\displaystyle Insertformulahere} 187: 177: 156: 82: 72: 51: 20: 1804:Mid-importance physics articles 653:{\displaystyle I_{xy}=\sum yxA} 508:For more information, refer to 240:This article has been rated as 135:This article has been rated as 573:18:43, 14 September 2011 (UTC) 1: 1462:21:17, 13 November 2013 (UTC) 1446:13:00, 10 February 2013 (UTC) 1238:12:31, 10 February 2013 (UTC) 1196:05:15, 15 February 2010 (UTC) 1172:17:00, 24 November 2009 (UTC) 1156:16:25, 24 November 2009 (UTC) 220:Knowledge:WikiProject Physics 214:and see a list of open tasks. 109:and see a list of open tasks. 98:WikiProject Civil engineering 1799:Start-Class physics articles 1350:09:04, 24 October 2010 (UTC) 1121:The definition is incomplete 607:10:45, 14 October 2009 (UTC) 420:11:51, 23 October 2023 (UTC) 223:Template:WikiProject Physics 1789:High-importance CE articles 461:02:49, 25 August 2006 (UTC) 341:Second moment of inertia = 297:21:18, 2 October 2018 (UTC) 1830: 1734:13:54, 24 March 2015 (UTC) 1689:18:02, 28 April 2013 (UTC) 1673:02:18, 28 April 2013 (UTC) 1643:23:00, 27 April 2013 (UTC) 1514:04:13, 14 April 2013 (UTC) 1367:00:37, 17 April 2012 (UTC) 514:Knowledge:Requested images 246:project's importance scale 141:project's importance scale 1708:05:44, 11 July 2013 (UTC) 1694:Current State of Momentum 1477:10:35, 1 April 2013 (UTC) 1414:01:55, 2 April 2012 (UTC) 1319:10:21, 13 June 2010 (UTC) 399:08:10, 11 July 2006 (UTC) 239: 172: 134: 67: 46: 1770:16:48, 19 May 2019 (UTC) 1390:12:31, 5 July 2011 (UTC) 1222:22:21, 14 May 2010 (UTC) 1106:19:22, 13 May 2007 (UTC) 559:19:45, 13 May 2007 (UTC) 331:04:29, 28 May 2007 (UTC) 317:04:30, 28 May 2007 (UTC) 1784:Start-Class CE articles 775:13:48, 6 May 2007 (UTC) 534:15:14, 2 May 2007 (UTC) 510:discussion on this page 485:It is requested that a 442:polar moment of inertia 1627: 1600: 1573: 1546: 1305: 1091: 1001: 761: 695:Product Moment of Area 687: 686:{\displaystyle I_{xy}} 654: 583:Product Moment of Area 538:"I-beam" cross section 512:and/or the listing at 481: 384: 28:This article is rated 1628: 1626:{\displaystyle I_{z}} 1601: 1599:{\displaystyle I_{y}} 1574: 1572:{\displaystyle I_{x}} 1547: 1545:{\displaystyle J_{z}} 1306: 1244:Parallel axis theorem 1092: 1002: 762: 688: 655: 480: 385: 1610: 1583: 1556: 1529: 1254: 1018: 786: 703: 667: 619: 438:Polar moment of area 345: 1272: 990: 889: 499:improve its quality 497:in this article to 390:rather than dA. .. 203:WikiProject Physics 1623: 1596: 1569: 1542: 1301: 1257: 1178:Rename the article 1087: 997: 973: 872: 757: 683: 650: 482: 380: 90:Engineering portal 34:content assessment 1676: 1659:comment added by 1517: 1500:comment added by 1373:Questionable link 1353: 1336:comment added by 1082: 1052: 992: 891: 693:is also known as 597:comment added by 521: 520: 517: 459: 422: 410:comment added by 299: 287:comment added by 260: 259: 256: 255: 252: 251: 151: 150: 147: 146: 112:Civil engineering 103:Civil engineering 59:Civil engineering 1821: 1762:Diego Torquemada 1675: 1653: 1632: 1630: 1629: 1624: 1622: 1621: 1605: 1603: 1602: 1597: 1595: 1594: 1578: 1576: 1575: 1570: 1568: 1567: 1551: 1549: 1548: 1543: 1541: 1540: 1516: 1494: 1352: 1330: 1310: 1308: 1307: 1302: 1288: 1287: 1268: 1096: 1094: 1093: 1088: 1083: 1081: 1080: 1071: 1070: 1061: 1053: 1051: 1050: 1041: 1040: 1031: 1006: 1004: 1003: 998: 993: 991: 989: 984: 969: 968: 959: 958: 948: 947: 946: 934: 933: 921: 920: 911: 910: 900: 892: 890: 888: 883: 868: 867: 858: 857: 847: 846: 845: 833: 832: 820: 819: 810: 809: 799: 766: 764: 763: 758: 692: 690: 689: 684: 682: 681: 659: 657: 656: 651: 634: 633: 609: 507: 473: 451: 444:... dead linkage 389: 387: 386: 381: 373: 372: 357: 356: 228: 227: 226:physics articles 224: 221: 218: 197: 192: 191: 181: 174: 173: 168: 160: 153: 123: 122: 119: 116: 113: 92: 87: 86: 76: 69: 68: 63: 55: 48: 31: 25: 24: 16: 1829: 1828: 1824: 1823: 1822: 1820: 1819: 1818: 1774: 1773: 1745: 1715: 1696: 1681:Chiraag.nataraj 1654: 1635:Chiraag.nataraj 1613: 1608: 1607: 1586: 1581: 1580: 1559: 1554: 1553: 1532: 1527: 1526: 1523: 1495: 1484: 1454:109.151.253.181 1421: 1397: 1392: 1375: 1331: 1326: 1276: 1252: 1251: 1246: 1180: 1123: 1114: 1072: 1062: 1042: 1032: 1016: 1015: 960: 950: 949: 935: 925: 912: 902: 901: 859: 849: 848: 834: 824: 811: 801: 800: 784: 783: 701: 700: 670: 665: 664: 622: 617: 616: 592: 585: 487:physics diagram 471: 428: 364: 348: 343: 342: 305: 265: 225: 222: 219: 216: 215: 193: 186: 166: 137:High-importance 120: 117: 114: 111: 110: 88: 81: 62:High‑importance 61: 32:on Knowledge's 29: 12: 11: 5: 1827: 1825: 1817: 1816: 1811: 1806: 1801: 1796: 1791: 1786: 1776: 1775: 1744: 1741: 1739: 1714: 1711: 1695: 1692: 1647: 1620: 1616: 1593: 1589: 1566: 1562: 1552:directly, not 1539: 1535: 1522: 1519: 1483: 1480: 1469:165.121.80.228 1465: 1464: 1435: 1434: 1431: 1428: 1420: 1417: 1396: 1393: 1380: 1374: 1371: 1370: 1369: 1359:86.176.166.181 1325: 1322: 1315:Fernando Estel 1300: 1297: 1294: 1291: 1286: 1283: 1279: 1275: 1271: 1267: 1264: 1260: 1245: 1242: 1241: 1240: 1225: 1224: 1210: 1209: 1204: 1203: 1202:mathematician. 1179: 1176: 1175: 1174: 1138: 1137: 1134: 1122: 1119: 1113: 1110: 1109: 1108: 1099: 1098: 1097: 1086: 1079: 1075: 1069: 1065: 1059: 1056: 1049: 1045: 1039: 1035: 1029: 1026: 1023: 1009: 1008: 1007: 996: 988: 983: 980: 976: 972: 967: 963: 957: 953: 945: 942: 938: 932: 928: 924: 919: 915: 909: 905: 898: 895: 887: 882: 879: 875: 871: 866: 862: 856: 852: 844: 841: 837: 831: 827: 823: 818: 814: 808: 804: 797: 794: 791: 756: 753: 750: 747: 744: 741: 738: 735: 732: 729: 726: 723: 720: 717: 714: 711: 708: 698: 697: 680: 677: 673: 661: 660: 649: 646: 643: 640: 637: 632: 629: 625: 599:145.236.252.34 584: 581: 580: 579: 578: 577: 576: 575: 547: 545: 544: 519: 518: 506: 483: 470: 467: 446: 445: 435: 427: 424: 379: 376: 371: 367: 363: 360: 355: 351: 338:Specifically: 335: 321: 304: 303:first comments 301: 276: 275: 272: 264: 261: 258: 257: 254: 253: 250: 249: 242:Mid-importance 238: 232: 231: 229: 212:the discussion 199: 198: 195:Physics portal 182: 170: 169: 167:Mid‑importance 161: 149: 148: 145: 144: 133: 127: 126: 124: 107:the discussion 94: 93: 77: 65: 64: 56: 44: 43: 37: 26: 13: 10: 9: 6: 4: 3: 2: 1826: 1815: 1812: 1810: 1807: 1805: 1802: 1800: 1797: 1795: 1792: 1790: 1787: 1785: 1782: 1781: 1779: 1772: 1771: 1767: 1763: 1759: 1756: 1753: 1752: 1748: 1742: 1740: 1737: 1735: 1731: 1727: 1722: 1718: 1712: 1710: 1709: 1705: 1701: 1693: 1691: 1690: 1686: 1682: 1677: 1674: 1670: 1666: 1662: 1658: 1651: 1645: 1644: 1640: 1636: 1618: 1614: 1591: 1587: 1564: 1560: 1537: 1533: 1520: 1518: 1515: 1511: 1507: 1503: 1499: 1491: 1488: 1481: 1479: 1478: 1474: 1470: 1463: 1459: 1455: 1450: 1449: 1448: 1447: 1444: 1440: 1432: 1429: 1426: 1425: 1424: 1419:Major cleanup 1418: 1416: 1415: 1411: 1407: 1403: 1394: 1391: 1387: 1383: 1382:NextThreshold 1379: 1372: 1368: 1364: 1360: 1356: 1355: 1354: 1351: 1347: 1343: 1339: 1335: 1323: 1321: 1320: 1316: 1311: 1298: 1295: 1292: 1289: 1284: 1281: 1277: 1273: 1269: 1265: 1262: 1258: 1249: 1243: 1239: 1236: 1232: 1227: 1226: 1223: 1219: 1215: 1212: 1211: 1206: 1205: 1200: 1199: 1198: 1197: 1193: 1189: 1183: 1177: 1173: 1169: 1165: 1164:77.215.191.91 1160: 1159: 1158: 1157: 1153: 1149: 1144: 1141: 1135: 1132: 1128: 1127: 1126: 1120: 1118: 1111: 1107: 1104: 1100: 1084: 1077: 1073: 1067: 1063: 1057: 1054: 1047: 1043: 1037: 1033: 1027: 1024: 1021: 1014: 1013: 1010: 994: 986: 981: 978: 974: 970: 965: 961: 955: 951: 943: 940: 936: 930: 926: 922: 917: 913: 907: 903: 896: 893: 885: 880: 877: 873: 869: 864: 860: 854: 850: 842: 839: 835: 829: 825: 821: 816: 812: 806: 802: 795: 792: 789: 782: 781: 779: 778: 777: 776: 773: 767: 754: 751: 748: 745: 742: 739: 736: 733: 730: 727: 724: 721: 718: 715: 712: 709: 706: 696: 678: 675: 671: 663: 662: 647: 644: 641: 638: 635: 630: 627: 623: 615: 614: 613: 610: 608: 604: 600: 596: 590: 582: 574: 570: 566: 562: 561: 560: 557: 552: 551: 550: 549: 548: 542: 541: 540: 539: 535: 532: 527: 524: 515: 511: 504: 500: 496: 492: 488: 484: 479: 475: 474: 469:Need diagrams 468: 466: 463: 462: 458: 454: 450: 443: 439: 436: 433: 432: 431: 425: 423: 421: 417: 413: 409: 401: 400: 397: 396:Gordon Vigurs 391: 377: 374: 369: 365: 361: 358: 353: 349: 339: 336: 333: 332: 329: 328:John.g.taylor 325: 322: 319: 318: 315: 314:John.g.taylor 311: 308: 302: 300: 298: 294: 290: 286: 279: 273: 270: 269: 268: 262: 247: 243: 237: 234: 233: 230: 213: 209: 205: 204: 196: 190: 185: 183: 180: 176: 175: 171: 165: 162: 159: 155: 142: 138: 132: 129: 128: 125: 108: 104: 100: 99: 91: 85: 80: 78: 75: 71: 70: 66: 60: 57: 54: 50: 45: 41: 35: 27: 23: 18: 17: 1760: 1757: 1754: 1749: 1746: 1738: 1723: 1719: 1716: 1697: 1678: 1655:— Preceding 1646: 1524: 1496:— Preceding 1492: 1489: 1485: 1482:Major Rework 1466: 1436: 1422: 1406:86.185.64.17 1401: 1398: 1376: 1327: 1312: 1250: 1247: 1184: 1181: 1145: 1142: 1139: 1130: 1124: 1115: 768: 699: 611: 586: 546: 537: 528: 525: 522: 509: 490: 486: 464: 447: 437: 429: 412:83.223.9.100 406:— Preceding 402: 392: 340: 337: 334: 326: 323: 320: 312: 309: 306: 283:— Preceding 280: 277: 266: 241: 201: 136: 96: 40:WikiProjects 1736:annahoward 1661:BeaumontTaz 1502:BeaumontTaz 1395:Readership? 1332:—Preceding 593:—Preceding 503:Graphic Lab 310:y=(h+h1)/4 289:90.43.11.93 121:CE articles 30:Start-class 1778:Categories 1726:Annahoward 1700:DPHutchins 1133:of a body? 1103:Hemmingsen 1439:Mecanismo 1324:Intuition 1231:Mecanismo 426:reverting 1669:contribs 1657:unsigned 1510:contribs 1498:unsigned 1346:contribs 1334:unsigned 1214:Kimaaron 1188:Cacadril 1148:Cacadril 595:unsigned 565:Mollynet 495:included 491:diagrams 408:unsigned 285:unsigned 1743:Polygon 1713:Updated 1521:Annulus 1317:☆ · 星 1131:surface 449:Nephron 263:Polygon 244:on the 217:Physics 208:Physics 164:Physics 139:on the 36:scale. 1402:don't 1338:G4oep 772:RJFJR 556:RJFJR 531:RJFJR 1766:talk 1730:talk 1704:talk 1685:talk 1665:talk 1650:this 1639:talk 1506:talk 1473:talk 1458:talk 1443:Talk 1410:talk 1386:talk 1363:talk 1342:talk 1235:Talk 1218:talk 1192:talk 1168:talk 1152:talk 603:talk 569:talk 416:talk 293:talk 131:High 1579:or 1313:-- 493:be 489:or 236:Mid 1780:: 1768:) 1732:) 1706:) 1687:) 1671:) 1667:• 1641:) 1512:) 1508:• 1475:) 1460:) 1441:| 1412:) 1388:) 1365:) 1348:) 1344:• 1233:| 1220:) 1194:) 1170:) 1154:) 1028:− 1022:σ 971:− 870:− 796:− 790:σ 639:∑ 605:) 571:) 536:) 516:. 505:. 418:) 362:∫ 295:) 1764:( 1728:( 1702:( 1683:( 1663:( 1637:( 1619:z 1615:I 1592:y 1588:I 1565:x 1561:I 1538:z 1534:J 1504:( 1471:( 1456:( 1408:( 1384:( 1361:( 1340:( 1299:y 1296:x 1293:A 1290:+ 1285:y 1282:x 1278:I 1274:= 1270:′ 1266:y 1263:x 1259:I 1216:( 1190:( 1166:( 1150:( 1085:y 1078:x 1074:I 1068:x 1064:M 1058:+ 1055:x 1048:y 1044:I 1038:y 1034:M 1025:= 995:y 987:2 982:y 979:x 975:I 966:y 962:I 956:x 952:I 944:y 941:x 937:I 931:y 927:M 923:+ 918:y 914:I 908:x 904:M 897:+ 894:x 886:2 881:y 878:x 874:I 865:y 861:I 855:x 851:I 843:y 840:x 836:I 830:x 826:M 822:+ 817:x 813:I 807:y 803:M 793:= 755:e 752:r 749:e 746:h 743:a 740:l 737:u 734:m 731:r 728:o 725:f 722:t 719:r 716:e 713:s 710:n 707:I 679:y 676:x 672:I 648:A 645:x 642:y 636:= 631:y 628:x 624:I 601:( 567:( 457:C 455:| 453:T 414:( 378:m 375:d 370:2 366:y 359:= 354:x 350:I 291:( 248:. 143:. 42::

Index


content assessment
WikiProjects
WikiProject icon
Civil engineering
WikiProject icon
icon
Engineering portal
WikiProject Civil engineering
Civil engineering
the discussion
High
project's importance scale
WikiProject icon
Physics
WikiProject icon
icon
Physics portal
WikiProject Physics
Physics
the discussion
Mid
project's importance scale
unsigned
90.43.11.93
talk
21:18, 2 October 2018 (UTC)
John.g.taylor
04:30, 28 May 2007 (UTC)
John.g.taylor

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.