*Thanks for the help*
Hint: Call the distance "D". Maybe you don't need the actual distance.
That's the one.
No, that's the weight of the particles--their attraction to the earth, not to each other.
*thanks for the help*
Just set Fel = Fgrav.
Get rid of that minus sign--you are comparing magnitudes.
You are almost there. Clean up the q & Q, m & M stuff: the charges are equal; the masses are equal (and given). Solve for the charge then plug in the numbers.
Looks good to me.
Many thanks for your help.... All I often need is a prod in the right direction
Separate names with a comma.