What is the magnitude of the uniform electric field

[salome]

Each of the electrons in a particle beam has a kinetic energy of 1.40 10-17 J.
(a) What is the magnitude of the uniform electric field (pointing in the direction of the electrons' movement) that will stop these electrons in a distance of 13.0 cm?
correct check mark N/C

(a) was 673 N

(b) How long will it take to stop the electrons?
wrong check mark
Your answer differs from the correct answer by 10% to 100%. ns
(c) After the electrons stop, the electric field will act on them, causing the electrons to accelerate in a direction correct check mark at what rate?
wrong check mark
Your answer differs from the correct answer by orders of magnitude. m/s2 i was not able to find the answers for par b and c and help would be appreciated! thanks

 

[K.J.Healey]

a : W = F d = q E d = K.E.
b : F = m a = q E && x = (1/2) a t^2
c : see above