How Do You Calculate Torque in a Beam Suspended by a Rope?

[mcdelilah]

Hi,

May someone please help me with this problem because there seems to be something that I am missing. I know that I am suppose to get the sum of all the external forces, and then set them to zero. Well, after my calculations, I am still wrong. The question is:

A beam of mass mb = 10.0 kg, is suspended from the ceiling by a single rope. It has a mass of m2 = 40.0 kg attached at one end and an unknown mass m1 attached at the other. The beam has a length of L = 3 m, it is in static equilibrium, and it is horizontal. The tension in the rope is T = 637 N.

 

[Doc Al]

I assume the problem is to find the unknown mass? Using the fact that the sum of the forces is zero is the correct approach. Show what you did and we can take a look.