Two cables A and B are attached to a hook. Cable A exerts a pull with a magnitude and direction defined by the vector A = 6i + 4k (kN). Cable B is also attached to the same hook where cable A is attached, cable B exerts a pull with a magnitude and direction defined by the equation B = -4i +7k (kN). What should be the magnitude of pull exerted at cable B such that the line of action of resultant force is along the positive z-direction (the resultant lies along the positive z-axis)? Express your answer in unit of kN.

Two cables A and B are attached to a hook. Cable A exerts a pull with a magnitude and direction defined by the vector A = 6i + 4k (kN). Cable B is also attached to the same hook where cable A is attached, cable B exerts a pull with a magnitude and direction defined by the equation B = -4i +7k (kN). What should be the magnitude of pull exerted at cable B such that the line of action of resultant force is along the positive z-direction (the resultant lies along the positive z-axis)? Express your answer in unit of kN.