tension

[tthaitanium]

a massless scaffold is held up by a wire at each end. the scaffold is 12 meters long. a 300 newton box sits 3 meters from the left end. what is the tension of each wire? please help

[Doc Al]

Identify all the forces acting on the scaffold. Since the scaffold is in equilibrium:
(1) The net force on it must be zero
(2) The net torque about any axis must be zero (use an end as the axis)

[Tjl]

Neglecting torque, the scaffold's center of mass will be proportionaly distanced in accordance to the tension on each string. This is a rather hairy calculation, so I would advise the use of Doc Al's method if you are familiar with how to calculate torque.