The distance between the cathode and anode in the gun of a certain cathode ray tube is 3.2 cm. If electrons are accelerated from rest through a potential difference of 9.1 x 10²V in this gun, with what kinetic energy do they emerge from the gun? Select one:
a. 7.2 x 10⁻²⁷J
b. 1.5 x 10⁻¹⁶ J
c. 4.6 x 10⁻¹⁵ J
d. 1.8 x 10⁷ J