Question

A horizontal uniform bar of mass 2.6kg and length 3.0m is hung horizontally on two vertical strings. String 1 is attached to the end of the bar, and string 2 is attached a distance 0.65m from the other end. A monkey of mass 1.3kg walks from one end of the bar to the other. Find the tension T1 in string 1 at the moment that the monkey is halfway between the ends of the bar.

Find T1, the magnitude of the force of tension in string 1, at the moment that the monkey is halfway between the ends of the bar.

Answer 1

the combined tension is ... T1 + T2 = (2.6 + 1.3) * g

when the monkey is halfway , all the downward force is centered in the middle of the bar

moments around T1
... [(2.6 + 1.3) * g] * (3.0 / 2) = T2 * (3.0 - 0.65)

solve for T2 , then substitute back to find T1