Please answer the following question. An electron is released from rest in a uni
ID: 1837785 • Letter: P
Question
Please answer the following question.
An electron is released from rest in a uniform electric field that has a magnitude of 5 times 10^4 V/m as shown in figure. The electron undergoes a displacement of 0.75 m in the direction of E, find: (A) The change in electric potential between points A and B. (B) The change in potential energy of the electron for this displacement. (C) The speed of the electron after completing the 0.75 m displacement in the electric field. The charge and the mass of the electron are q = -1.6 times 10^-19C, and m = 9.11 times 10^-31 kg, respectively.Explanation / Answer
(A) change in electric potential VB -VA = E.d = (5 x 10^4 V/m) (0.75m) = 37500 Volt
(B) change in PE = - q (VA - VB)
= - (-1.6 x 10^-19) (-37500) = -6 x 10^-15 J
(C) Applying energy conservation,
KE + PE at A = KE + PE at B
0 + 0 = m v^2/2 + ( - 6 x 10^5)
(9.11 x 10^-31 ) v^2 / 2 = 6 x 10^5
v = 1.15 x 10^8 m/s