Question

a uniform 163 kg, 6m beam is held at rest by a vertical post s=2 m from its right end, and a vertical cable attached to its right end. A 92 kg man stands at the left end of the beam, d= 4m from the post.

a. create a complete FBD for the beam.

b. if we choose the piont where the post contacts the beam as axis for the purpose of calculating torques acting on the beam, which one of the forces in your FBD will generate no torque at all? Explain.

c. Identify the forces in your FBD that generate clockwise torques about this axis:

d. write a N2L expression relating the torques acting on the beam, only using symbols and assuming the beam is in quilibrium.

e. solve our N2L expression and calculate the tension in the cable.

Answer 1

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(a)FBD:

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(b)

The force does not generate torque is Fx, Fy that are located at the point
another force that does not generate torque is the horizontal component of the tension because it has no arm action and is aligned with the axis.

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(c)

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(d)

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(e)

Then substituting in the equation: