[填空题]
An electron moving to -lg- n9-wh c3r)9 fdbdct otv s2zy-l/the right at 1.0% the speed of light enters a uniform eleh6q,ks6q1b.h3p 03 eyc bk ju7w(qbk ectric field parallel to its direction of motion. If the elcb.( yebbhphqk,qwksjk633 7 q e 01u6ectron is to be brought to rest in the space of 4.0 cm,
(a) what direction is required for the electric field,
(b) what is the strength of the field? N/C
