Question

Item 5 How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 4.57102wiens? I Review Two small spheres spaced 20.0 centimeters apart have equal charge electrons Submit Reguest Answer

This is what I did, but my answer did not come out right.

Answer 1

let magnitude of charge be q

force between the charges is given by

F=9*10⁹*q²/r² = 9*10⁹*q²/0.2²=2.25*10¹¹q²

Given force = 4.57*10^-21 N

2.25*10¹¹q² = 4.57*10^-21

q=1.42*10^-16 C

charge on each electron = 1.6*10^-19 C

number of excess electron on each sphere = 1.42*10^-16/1.6*10^-19 = 887