如图所示,A、B、C、D是某匀强电场中的4个等势面,一个质子和一个

如图所示,A、B、C、D是某匀强电场中的4个等势面,一个质子和一个α粒子(电荷量是质子的2倍,质量是质子的4倍)同时在A等势面从静止出发,向右运动,当到达D面时,对于质子和α粒子:(不计粒子重力)
①     电场力做功之比为:2∶1  
② 电场力做功之比为:1:2
③ 它们的速度之比为::1 
④ 它们的动能之比为:1:2
A、①③④     B、②③④      C、②④      D、①③

答案

B

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