A long, rigid conductor, lying along the x axis, carries a current of 4.0 A in the negative direction. A magnetic field B is present, given by B = 2.5i + 8.5x2 j , with x in meters and B in mT. Calculate the k-component of the force on the 2 m segment of the conductor that lies between x = 1.0 m and x = 3.0 m.