An electron is released from rest at the negative plate of a parallel-plate capacitor. If the distance across the plates is 5.0 mm and the potential difference across the plates is 20 V, with what velocity does the electron hit the positive plate? (m_e = 9.1 * 10 ^- ³¹ kg, e = 1.6 *10 ^- ¹⁹ C)

Question

Quizplus · Accepted Answer

The kinetic energy gained by the electron equals the work done by the electric field, which is the charge times the potential difference: KE = eV. Solving for velocity using KE = 0.5 * m * v^2 gives v = sqrt(2 * e * V / m). Substituting the given values results in approximately 2.7 x 10^6 m/s.

An Electron Is Released from Rest at the Negative Plate