A horizontal uniform bar of mass 2.6 and length 3.0 is hung horizontally on two vertical strings. String 1 is attached to the end of the bar, and string 2 is attached a distance 0.7 from the other end. A monkey of mass 1.3 walks from one end of the bar to the other. Find the tension in string 1 at the moment that the monkey is halfway between the ends of the bar.