# Electrostatic/gravitational force q

1. Jan 29, 2007

### debwaldy

1. The problem statement, all variables and given/known data
Determine the ratio of the electrostatic to the gravitational force between an electron and a proton

2. Relevant 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

3. 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 im going wrong somewhere,either in my methodology or figures
any help would be much appreciated
thanks debs
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Jan 29, 2007

### Kurdt

Staff Emeritus
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.

3. Jan 30, 2007

### debwaldy

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