What is the acceleration of the electron in this region and how long is the electron in the region where it accelerates?An electron in a cathode...

The acceleration of an object can be calculated by the
formula:

a = (v^2 -
u^2)/2s

where:

u = Initial
velocity

v = Final Velocity

s
= Distance travelled during increase of velocity from u to
v.

Substituting the given values of u, v, and s for the
electron in the above equation for distance:

s =
[(1.5x10^6)^2 - (3.5x10^4)^2]/[2x(2/100)]

= (2.25x10^12 -
12.25x10^8)/0.04

= (2.25x10^10 -
12.25x10^6)/4

=
(2.248775x10^10)/4

= 5621937.5x10^3
m/s^2

The time (t) taken to accelerate is given
by:

t = (v - u)/a

Substituting
the values of u, v and a in above equation:

t = (1.5x10^6 -
3.5*10^4)/(5621937.5x10^3)

=
(1.4658x10^3)/5621937.5

= 0.0002591277
s