The particle of Problem 16.4 is initially at rest in a spatially uniform, but time-varying electric field E(t)=E0Θ(t).
(a) Show that its speed in the direction of the field is given by the integral
v(t)=−πceE0a∫−∞∞dξξ2M(ξ)e−iTξ
where T=ct/2a.
(b) From the analytic properties of M(ξ) established in part c of Problem 16.4, show that v(t)=0 for t≤0 (no preacceleration).