磁力火车实验现象的理论解释

Theoretical explanation of the experimental results of magnetic train

从理论上解释了磁力火车实验中观察到的现象.计算了火车受到的磁场力,指出火车两端的磁铁必须是同名磁极相对的原因.推导出火车运动速率的表达式,证明火车运动速率的增幅越来越小,最终火车会匀速率运动.从匀速率运动时的速率表达式可以看出:干电池的电动势越大,匀速率越大;而随着磁铁磁偶极矩的增大,匀速率则先增大后减小.

The experimental results of magnetic train were explained theoretically.After obtaining the expression of the force on magnetic train,it was found that the adjacent poles of two magnets must be the same.According to the expression of the speed of the magnetic train,the increasing rate of the speed became smaller and smaller,and the magnetic train would move at a constant speed in the end.Furthermore,from the expression of the final speed,the greater the eletromotive force of the battery was,the greater the speed would be;whereas,the final speed would firstly increase and then decrease with the increasing of the magnetic dipole moment.