일반물리학 2 — Electric Fields: Problem 39

39 A uniform electric field exists in a region between two oppositely charged plates. An electron is released from rest at the surface of the negatively charged plate and strikes the surface of the opposite plate, 3.0 cm away, in a time $1.5 \times 10^{-8}$ s. Just as the electron strikes the second plate, what are its (a) momentum magnitude and (b) kinetic energy? (c) What is the magnitude of the electric field $\vec{E}$?