PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Electric Force Field and Potential · Electric Force Field and Potential
Problem
A beam of alpha particles (charge +2e, mass mα=6.64×10−27kg) is first accelerated through a potential difference of 4.0kV and then enters a second accelerating region. The design goal is for the particles to emerge from the second region with a speed of 9.0×105ms−1. Neglect any forces other than those due to the applied electric fields.
(a) Determine the speed of an alpha particle after the first 4.0kV acceleration.
(b) Calculate the additional potential difference required in the second region so that the particle exits with the desired final speed.
(c) Explain how your answer to part (b) would change, if at all, if the first accelerating stage had provided 6.0kV instead of 4.0kV. Justify your response without repeating the full calculation.