1700993440
一级近似：二级近似：
1700993441
1700993442
1700993443
1700993444
7-63 平衡位置：
1700993445
1700993446
1700993447
1700993448
θ＝0：当时为稳定平衡，当时为不稳定平衡；
1700993449
1700993450
θ＝π：不稳定平衡；
1700993451
1700993452
1700993453
稳定平衡．
1700993454
1700993455
1700993456
7-64
1700993457
1700993458
1700993459
7-65
1700993460
1700993461
7-66 （1）6.18×10-2J； （2）3.0×10-2W．
1700993462
1700993463
1700993464
7-67
1700993465
1700993466
第 八 章
1700993467
1700993468
1700993469
8-1
1700993470
1700993471
1700993472
8-2
1700993473
1700993474
1700993475
8-3
1700993476
1700993477
1700993478
8-4
1700993479
1700993480
1700993481
8-5
1700993482
1700993483
1700993484
1700993485
8-6 轨迹方程为直线斜率为
1700993486
1700993487
1700993488
1700993489
