A Pair of Charged Conducting Plates Produces a Uniform Field

Multiple Choice

A pair of charged conducting plates produces a uniform field of 12,000 N/C, directed to the right, between the plates. The separation of the plates is 40 mm. An electron is projected from plate A, directly toward plate B, with an initial speed of v₀ = 2.0 × 10⁷ m/s. What is the speed of the electron as it strikes plate B? (e = 1.6 × 10^-19 C, m_electron = 9.11 × 10^-31 kg)

A) 1.2 × 10⁷ m/s
B) 1.5 × 10⁷ m/s
C) 1.8 × 10⁷ m/s
D) 2.1 × 10⁷ m/s
E) 2.4 × 10⁷ m/s