To solve this problem we will apply the concepts related to electrostatic energy, defined as,
[tex]U_e = \frac{kq_1q_2}{d^2}[/tex]
Here,
k = Coulomb's constant
[tex]q_{1,2}[/tex] = Charge of each object (electron and proton, at this case the same)=
d = Distance
Replacing with our values we have that
[tex]U_e = \frac{(9*10^9Nm^2)(1.6*10^{-19}C)(-1.6*10^{-19}C)}{0.0539*10^{-9}m}[/tex]
[tex]U_e = -4.27*10^{-18}J[/tex]
Therefore for the Part A the answer is [tex]-4.27*10^{-18}J[/tex] and por the Part B the sign indicates that the force between the proton and electron is attractive
