The potential difference between the plates of a capacitor is 70 V. Midway between the plates, a proton and an electron are released. The electron is...

The potential difference between the plates of a capacitor is 70 V. Midway between the plates, a proton and an electron are released. The electron is released from rest. The proton is projected perpendicularly toward the negative plate with an initial speed. The proton strikes the negative plate at the same instant that the electron strikes the positive plate. Ignoring the attraction between the two particles, what was the initial speed of the proton?