A horizontal uniform bar of mass 2.6 kg and length 3.0 m is hung horizontally on two vertical strings. String 1 is attached to the end of the bar, and string 2 is attached a distance 0.6 m from the other end. A monkey of mass 1.3 kg walks from one end of the bar to the other. Find T_1 , the magnitude of the force of tension in string 1, at the moment that the monkey is halfway between the ends of the bar.