Relativistic motion of an electron in a uniform electric field

[Natchanon]

Homework Statement

Solve for velocity and position as a function of time

Relevant Equations

attached in the .png file, where electric field E and tau are constants.

dv/dt is the acceleration, so I thought I could find the acceleration from F = qE = ma = dp/dt. But this is a relativistic case, so the proper acceleration is a = F/mγ³, where v in the gamma is the v of the electron and F = eE. However, I'm not sure if this is correct, because the constant τ doesn't appear anywhere on the right side.

 

[Abhishek11235]

Please post full question and show your attempt