Answer:
r = 5.09m
Step-by-step explanation:
Weight of an electron is:
W = m*g
W = 9.11 * 10^(-31) * 9.8
W = 8.93 * 10^(-30)N
Electric force between two electrons is given by:
F = kq²/r²
Where
k = Coulumbs constant
q = charge of electron = 1.602 * 10^(-19) C
r = distance between both electrons
If weight is equal to electric force,
8.93 * 10^(-30) = (9 * 10^ 9 * (1.602 * 10^(-19))²/r²
=> r² = (9 * 10^ 9 * (1.602 * 10^(-19))²) / 8.93 * 10^(-30)
r² = 25.9
r = 5.09m
They must be 5.09m apart for the electric force to be equal to the weight of an electron.