Hi there!
The equation for the electric field of a point charge is given by:
E = Electric Field (N/C)
k = Coulomb's Constant
r = distance (m)
We can rearrange to solve for 'q':'
Plug in the values and solve:
Be better. if the ramp had some sort of smoothing to it, it would make what ever your roll down it go much faster. sorry for the short answer