Of the charge Q initially on a tiny sphere, a portion q is to be transferred to a second, nearby sphere. Both spheres can be treated a particles. For what value of q/Q will the electrostatic force between the two parts have 1/4 of the maximum possible value? q1=Q when the charge is transferred its Q - q q2=0 becomes q after transfer F = K(|q1||Q-q|)/r^2 dF(q)/dq = 0 0 = dF/dq = K/r^2 d/dq (qQ - q^2) then Q - 2q = 0 so q = Q/2 so Fmax is 1/2 My question is, where do i apply the 1/4 of the max. value? im rather confused. I thought it would just be 1/4 of the max. any help would be appreciated. thanks.