Quiz

Actually, I was wrong. All my arguments would be relevant in the case where an electron would fly through the positive plate... because, in reality, the electric field is directed from the positive plate to the negative plate, so the field would also accelerate it in this capacitor, and it would reach the opposite plate, and its speed would be greater. But even if it were to fly through the positive plate at that speed, it would still reach the negative plate, as in such a field, it could travel more than 7 millimeters in its initial direction, and the distance between the plates is only 1 mm.

Added 2 minutes later
Well, 1 millimeter is the answer.