An old TV picture tube accelerates electrons through thousands
of volts. A glass chamber holds the vacuum to ensure that electrons do
not collide with air molecules.


(a)If the TV is laid on its back, facing up toward the ceiling, would the
electrons be able to fly upward against gravity? Give your
reasoning.

(b)What voltage (a.k.a. potential difference) acting over a 3.5 cm
distance (the size of a typical electron gun inside the TV) would be
needed to balance the downward force of gravity so that the
electrons would remain stationary?
[You can assume that the electric field is uniform]