Solving a problem in physics section 17 paragraph 82 el

82. Initially, the electron flies freely with velocity υ0. At time t = 0 is switched uniform electric field strength E, forms with the direction υ0 angle α.
a) At what path the electron moves after the field?
b) What is a radius of curvature R of the trajectory at the point where the electron velocity is minimal?
c) What is the electron momentum increment Ap in the time τ?
d) How to change with time of the angular momentum of the electron module M with respect to the point at which the electron is at the moment when the field?