题目

 图甲所示的平行板电容器板间距离为d，两板所加电压随时间变化图线如图乙所示，t=0时刻，质量为m、带电量为q的粒子以平行于极板的速度V0射入电容器，t1=3T时刻恰好从下极板边缘射出电容器，带电粒子的重力不计，求：（1）平行板电容器板长L；（2）子射出电容器时偏转的角度φ；（3）子射出电容器时竖直偏转的位移y。图甲  图乙            I don't believe this advertisement. That kind of mobile phone is it says.A. not as better as B. not as good asC. not as well as D. not the same good as