A small bead of mass \(m = 0.050\text{ kg}\) and positive charge \(q = +0.020\text{ C}\) is constrained to slide without friction along a straight, horizontal insulating wire aligned with the \(x\)-axis. In this region, the electric potential as a function of position along the wire is given by \(V(x) = 125 - 5.0x^2\), where \(V\) is in volts and \(x\) is in meters. The bead is released from rest at \(x = 0\). What is the speed of the bead when it reaches \(x = 4.0\text{ m}\)?