A proton gun fires a proton from midway between two plates, A and B,which are separated by a distance of 10.0cm; the proton initially moves at a speed of 150 km/s toward plate B. Plate A is kept at zero potential and plate B is kept at a potential of 400.0V
1) will the proton reach plate B?
2) If not, where will it turn around?
3) with what speed will it hit plate A?