For the answer to the question above, <span>a) Use F = k * q1 * q2 / d² where k = 8.99e9 N·m²/C² and q1 = -1.602e-19 C (electron) and q2 = 1.602e-19 C (proton) and d = distance between point charges = 0.53e-10 m The negative result indicates "attraction".
b) Here, just use F = ma where F was found above, and m = mass of electron = 9.11e-31kg, if memory serves a = radial acceleration
c) Now use a = v² / r where a was found above and r was given
d) period T = 2π / ω = 2πr / v where v was found above and r was given </span>