Question

Use the following values for mass and charge: an electron has mass me = 9.11×10-31 kg and charge -e, a proton has mass mp = 1.67×10-27 kg and charge +e, an alpha particle has mass malpha = 6.65×10-27 kg and charge +2e, where e = 1.60×10-19 C. An electron is released from rest in a vacuum between two flat, parallel metal plates that are 13.0 cm apart and are maintained at a constant electric potential difference of 780 Volts. If the electron is released at the negative plate, what is its speed just before it strikes the positive plate?