The mass of an electron is 9.109×10−31 kg, and the magnitude of the charge of an electron is 1.602×10−19 C. What is the ratio of the gravitational force to the electrostatic force between two electrons?

Question

3.093×10^22

4.165×10^42

3.233×10^−23

2.390×10^−43

Can someone please help, i'm so confused.

Answer 1

electro:
Fe= k Q1 Q2 /d^2 = 9 * 10^9 *(1.6*10^-19 )^2 / d^2
gravity:
Fg = G M1 M2 /d^2= 6.7*10^-11* (9.1*10^-31)^2 / d^2

ratio:
Fg/Fe = 6.7*10^-11* (9.1*10^-31)^2 / 9 * 10^9 *(1.6*10^-19 )^2

(gravity loses huge for small objects with serious charge)

Answer 2

the answer is 2.390 x 10^-43