An electron (m = 9.1 × 10−³¹ kg, q = −1.6 × 10−¹⁹ C) starts from rest at point A and has a speed of 5.0 × 10⁶ m/s at point B. Only electric forces act on it during this motion. Determine the electric potential difference V_A − V_B.

Question

Quizplus · Accepted Answer

The electric potential difference is given by:$$V_A - V_B = \frac{1}{2}mv_B^2$$$$V_A - V_B = \frac{1}{2}(9.1 	imes 10^{-31} 	ext{ kg})(5.0 	imes 10^6 	ext{ m/s})^2$$$$V_A - V_B = -71 	ext{ V}$$Therefore, the correct answer is A.

An Electron (M = 9