Gravitational force between a proton and electron at 2.8 m

[ali13]

Homework Statement

A single proton and a single electron are fixed at a distance of 2.8 meters from each other. Find the magnitude of the electric force of attraction between them.

i have the answer to this, it is: 2.93*10^-29

but now it asks: Find the magnitude of the gravitational force of attraction between the proton and the electron. (Mass of a proton = 1.67 x 10-27 kg; Mass of an electron = 9.11 x 10-31 kg)

i'm not sure where to put gravity, 6.67 * 10^-11, in the equation:

F=k*Q*q/r2

thank you!

 

[tiny-tim]

welcome to pf!

hi ali13! welcome to pf!

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i'm not sure where to put gravity, 6.67 * 10^-11, in the equation:

F=k*Q*q/r2

F = GMm/r²