a. Determine the potential difference of the electric field between points 1 and 2, if it is known that the electron moving in this electric field in the absence of other forces, at point 1 had a speed of 10^9 cm/s, and at point 2 — a speed of 2⋅10^9 cm/s. What would be the electron velocity at point 2 if the electron had zero velocity at point 1?
b. In an electron tube, electrons are accelerated by a potential difference of 220 V. What is the speed of electrons when they hit the anode?