电磁场的能量和动量

The energy and momentum in electromagnetic fields

通过分析匀强磁场中平行板电容器内导体棒的运动,把电磁场的能量和动量这两个较为抽象的概念具体化．运用这一简单的模型分析并论证了电磁场具有能量和动量,且可与机械动能和动量相互转换,在转换过程中遵循守恒定律．

The abstraction of energy and momentum in electromagnetic fields is concretized through analyzing the movement of conducting rod in parallel plate capacitor in a uniform magnetic field. It can be shown that energy and momentum exist indeed in electromagnetic fields and can be transformed into or from kinetic energy and mechanical momentum. And the conservation law is obeyed during the process of transformation.