- #1

huskydc

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A man of mass mm = 95 kg decides to paint his house. To do this, he builds a platform using a uniform beam with a mass of mb = 100 kg and a length of L = 7 meters. The beam is supported by two sawhorses, as shown in the diagram above.

If the man stands over the support at point B, calculate the force exerted by the beam on the support at A.

--at first, i misread the question and thought it's asking for the force exerted by A on the beam.

and I did the following:

F(A) + F(B) - F(b) - F(m) = 0

and have B as the pivot,

thus with the torque of A = -3 F(A)

and torque of beam (b) = .5 F(b)

, but now it's asking of the F exerted by beam on support at A? I'm confused here....its one whole beam, i'm assuming the force excerted by the beam will occur at the center of mass.....help

If the man stands over the support at point B, calculate the force exerted by the beam on the support at A.

--at first, i misread the question and thought it's asking for the force exerted by A on the beam.

and I did the following:

F(A) + F(B) - F(b) - F(m) = 0

and have B as the pivot,

thus with the torque of A = -3 F(A)

and torque of beam (b) = .5 F(b)

, but now it's asking of the F exerted by beam on support at A? I'm confused here....its one whole beam, i'm assuming the force excerted by the beam will occur at the center of mass.....help