共查询到18条相似文献,搜索用时 62 毫秒
1.
2.
3.
本文特别指明,应用柯尼希定理处理系统动能时,首要意义是将系统动能分为系统整体的质心动能和系统内部的有效动能,在这样的认识下运用柯尼希定理,其方法意义才得以充分体现. 相似文献
4.
用三线摆对刚体薄圆盘绕不同轴转动时的转动惯量进行测量,通过实验与数据分析,验证了反映刚体转动惯量重要性质的垂直轴定理,从而实现了对刚体转动惯量实验内容的扩充. 相似文献
5.
质心运动定理∑F=ma是刚体力学中的一个基本规律,是教学重点之一.为使学生理解质心运动定理及由此导出的结论,我们设计了下面的演示实验,验证静止刚体受力偶的作用时,刚体绕质心转动,而不是绕力偶中心转动. 相似文献
6.
阐述在刚体的定点转动中,引入"自然坐标系"来分析,往往可以使问题变得更加简单,物理意义变得更加清晰,并且通过具体实例加以验证,最后通过对刚体定轴转动的分析,把刚体定轴转动的角动量定理与定点的角动量定理统一起来. 相似文献
7.
质心运动定理演示实验 总被引:1,自引:1,他引:0
引言 质心运动定理∑F=ma。是刚体力学中的一个基本规律,是这个部份的教学重点之一。为使学生理解质心运动定理及由此导出的结论,我们设计了下面两个演示实验。 实验一 验证静止刚体仅受力偶的作用时,刚体绕质心转动,而不是绕力偶中心转动。 1.原理和设计思想静止刚体在一力偶的作用下,所受的合外力为零,根据质心运动定理,质心的加速度为零。如刚体原来静止,则在力偶作用下,质心不动,刚体绕共质心转动。应该注意,质心运动定理与外力的作用点无关,即无论力偶作用在刚体的什么地方,刚体总是绕其质心转动。例如图1所示为浮在水面上的木棒,当力… 相似文献
8.
9.
10.
本文导出了一般运动刚体的速度最小值、速度量小值点的位矢、速度最小值点加速度的数学表达式.通过这些公式的讨论验证了一般运动刚体瞬时螺旋轴的存在,给出了清晰的物理图象和几何图象;把潘索定理推广到刚体的一般运动情形,给出了一般运动刚体上任一点速度的又一求法.作为其特例讨论了刚体的定点转动和平面平行运动. 相似文献
11.
提出并证明了一个关于刚体转动惯量的新定理.该定理指出具有对称面的均质刚体,当位于与对称面垂直的某个平面上的转轴满足特定条件时,转动惯量大小与位于该平面上的转轴方向无关. 相似文献
12.
Gregory J. Galloway 《Communications in Mathematical Physics》1984,96(4):423-429
A Lorentzian splitting theorem is obtained for spatially closed spacetimes. The proof employs and extends some recent results of Bartnik and Gerhardt concerning the existence and rigid uniqueness of compact maximal hypersurfaces in spatially closed space-times. A splitting theorem for spatially closedtime-periodic space-times, which generalizes a result first considered by Avez, is derived as a corollary. 相似文献
13.
The validity of the Gyarmati theorem has been extended to non-linear types of constitutive equations governing dissipative processes which have recently been suggested. It has been proved that by extending the validity of the theorem, the validity of Gyarmati's variational principle of thermodynamics is guaranted for non-linear theories adequate to constitutive equations in question as well. The theory was applied for stationary temperature distribution in a rigid bar. 相似文献
14.
任意多边形匀质刚板绕垂直板面质心轴的转动惯量的几何求法 总被引:8,自引:4,他引:4
利用改造后的平行轴定理,提出了一种推导任意多边形匀质刚板绕质心轴的转动惯量的几何方法,并用这种方法推导出任意三角形和五边形匀质刚板绕质心轴的转动惯量公式。 相似文献
15.
16.
We evaluate thermal noise (Brownian motion) in a rigid reference cavity used for frequency stabilization of lasers, based on the mechanical loss of cavity materials and the numerical analysis of the mirror-spacer mechanics with the direct application of the fluctuation dissipation theorem. This noise sets a fundamental limit for the frequency stability achieved with a rigid frequency-reference cavity of order 1 Hz/ square root Hz (0.01 Hz/ square root Hz) at 10 mHz (100 Hz) at room temperature. This level coincides with the world-highest level stabilization results. 相似文献
17.
We study the problem of motion of a relativistic, ideal elastic solid with free surface boundary by casting the equations
in material form (“Lagrangian coordinates”). By applying a basic theorem due to Koch, we prove short-time existence and uniqueness
for solutions close to a trivial solution. This trivial, or natural, solution corresponds to a stress-free body in rigid motion. 相似文献
18.
The elastic interaction of certain point singularities with a rigid spherical inclusion embedded into an otherwise infinite elastic medium is investigated. The particular singularities considered are point force, force-dipole (with and without moment), centre of dilatation and concentrated moment. In each case, simple, closed form expressions are deduced by application of Betti's reciprocal theorem for the net force and net torque acting on the inclusion. 相似文献