电磁场中的动量流的探讨

牛顿第二定律相当于动量的积分形式的连续方程。这个见解提供了依据动量流的一种力的图象的选择。动量流的选择导致了麦克斯韦应力张量的表示。麦克斯韦应力张量是容易设想定量地画出草图,且提供了几个简单例子动量流分布的计算草图。

Newton's second law is eqwivalent to the continuity equation for momentum in integral form. This insight provides an an alternative picture of forces in terms of momentum currents. The momentum current picture leads to a representation oe Max well's stress which is easy to . visualiye and to shctch quantitatively. Computer sketches of the momentum current distributions for a few simple examples are presented.