The force acting on the electron from the nucleus of the hydrogen atom is 3.6967 • 10-10 n
The electron mass is me = 9.10938356 • 10-31 kg ...
In order to accelerate the electron to a velocity of 0.5 C = 0.5 • 2.998 • 108 m / sec for 10-17 seconds, it is necessary to exert force -
V = V0 + (T1-T2) • F / me
The electron in the hydrogen atom has V0 = 0 - conditionally ...
F = V • me / (T1-T2) = 0.5 • 2.998 • 108 m / s • 9.10938356 • 10-31 kg / 10-17 seconds = 13.655 • 10-6 kgm / sec2 =1.4 • 10-5 N
By Geek3 - Own work, CC BY-SA 3.0, Link