A parallel plate capacitor has two conducting plates seperated by a vacuum. The distance is D and the area of each plate is A.
An alpha particle with mass M and charge Q is placed on the positively-charged plate, between the plates. It shoots through a small hole in the negatively charged place with speed S.
What is the magnitude of the uniform electric field between the plates?
How much charge lies on the positively-charged plate?
How much energy is stored in the capacitor's electric field?
The Attempt at a Solution
For the first question, I can find the capacitence, C=(epsilon_0)(A/D), but I'm not sure where to go from here.
For the second question, I could find Q using C=Q/V and use V=Ed but I need E from the first question that I don't know how to find!
I'm not sure where the alpha-particle comes in to play!?