Savchenko Problem 7.1.10
Physics
Problem
An electron moving with velocity v passes from the field region with potential to the region with potential . At what angle will the electron move to the interface of the regions, if it flew to it at an angle ?Intuitive explanation
The electron's kinetic energy changes as it crosses the potential boundary, which alters its speed but not the component of velocity parallel to the interface. Think of this like refraction: the perpendicular component of velocity changes due to the work done by the electric field, while the tangential component stays constant. Use energy conservation to find the new speed, then apply the constraint that the parallel velocity component doesn't change to find the new angle.
Intuitive explanation
The electron's kinetic energy changes as it crosses the potential boundary, which alters its speed but not the component of velocity parallel to the interface. Think of this like refraction: the perpendicular component of velocity changes due to the work done by the electric field, while the tangential component stays constant. Use energy conservation to find the new speed, then apply the constraint that the parallel velocity component doesn't change to find the new angle.