a.
$ E = \dfrac{{k.\left| Q \right|}}{{{r^2}}} = \dfrac{{{{9.10}^9}.\left| {{{10}^{ - 5}}} \right|}}{{0,{1^2}}} = 0,{9.10^7}(V/m) $
b.
$ F = \dfrac{{k.\left| {{q_1}.{q_2}} \right|}}{{{r^2}}} = \dfrac{{{{9.10}^9}.\left| {{{10}^{ - 5}}{{.2.10}^{ - 5}}} \right|}}{{0,{1^2}}} = 180N $