A4m, 500kg steel beam extends horizontally from thepoint where it has been bolted to the framework of a new buildingunder construction. a 70kg worker stand at the far end of the beam. what is the magnitude of the torque about the point where the beamis bolted into place.
now this is what i have:
τ (grav)=-mgxcm where mg is the net gravitational forceacting on the object and xcm is the moment arm between the rotationaxis and center of mass.
=2.13 from the rotation point (where the building is bolted)
now the problem i think i am having is finding the net forceon the object. i thought it was the total mass of the object(570kg) times gravity (9.8)
this give the final answer to be
-(570)(9.8)(2.13)=-11898.18nm but that is not the answer. theanswer is -12500nm.
any would be appreciated.