Three point charges are arranged along the x axis. Charge q1 = -4.10 nC is located at x= 0.250 mand charge q2 = 2.20 nC is at x= -0.320 m . A positive point charge q3 is located at the origin.

What must the value of q3 be for the net force on this point charge to have magnitude 3.10 μN ? (ans in nC)

What is the direction of the net force on q3? + or - direction

Where along the x axis can q3 be placed and the net force on it be zero, other than the trivial answers of x=+[infinity] and x=−[infinity]? (ans in m)