Fix magnets in pairs onto a metal sheet as shown. If you attach two magnetic discs onto an axle this “vehicle” will accelerate over the rows of magnets under certain conditions. Investigate the phenomenon.

如图所示，将磁铁成对固定在金属板上。如果将两个磁性圆盘安装在一根转轴上组成“小车”，在特定条件下，这个“车辆”会在磁铁排上加速。研究这一现象。