We consider next the electric field set up by a long thin uniformly charged wire.
我们接着讨论由一细长、均匀带电的直导线所产生的电场。
Sports a metal ball weighing 'pounds (7.2 kilograms) and having a long wire or wooden handle by which it is thrown for distance in track-and-field competition.
由重'磅(7.2千克)的金属球和一条长链或木把手组成，人手持链端或把手在田径比赛中将其投远以争高低。
A metal ball weighing16 pounds (7. 2 kilograms) and having a long wire or wooden handle by which it is thrown for distance in track - and - field competition.
链球由重16磅(7。2千克)的金属球和一条长链或木把手组成，人手持链端或把手在田径比赛中将其投远以争高低。
A metal ball weighing16 pounds (7. 2 kilograms) and having a long wire or wooden handle by which it is thrown for distance in track - and - field competition.
链球由重16磅(7。2千克)的金属球和一条长链或木把手组成，人手持链端或把手在田径比赛中将其投远以争高低。
应用推荐