Electrostatic/gravitational force q

[debwaldy]

Homework Statement

Determine the ratio of the electrostatic to the gravitational force between an electron and a proton

Homework Equations

I wasn't too sure where to start with this so i used the following equations:
Electrostatic force f = (charge on proton*charge on e-)/(4*pi*epsilon*d^2)

and gravitational force p = G*m1*m2/(4*pi*d^2)

where:
epsilon = 8.854187*10^-12
charge on Proton = +1 C
charge on electron = 1.6*10^-19
G = 6.67*10^-11
mass of proton = 1.6726231*10^-27
mass of e- = 9.109*10^-31

The Attempt at a Solution

then i said f/p = (1.6*10^-19)(1)/(4*pi*epsilon*d^2)/(6.67*10^-11)*(9.109*10^-31)(1.6726*10^-27)/(4*pi*d^2)


f/p = 1.414459*10^58


is this answer correct, i have a feeling I am going wrong somewhere,either in my methodology or figures
any help would be much appreciated
thanks debs

 

[Kurdt]

For your attempt at the solution I believe the 1 in brackets is supposed to be the charge of a proton. The charge of a proton is not 1 coulomb, it is exactly the same magnitude as the charge on an electron but with the opposite sign.

 

[debwaldy]

thanks a million,wasn't too sure about that one but it obviously makes sense that way!