? asked in Science & MathematicsPhysics · 2 years ago

What is the magnitude of the force of the post nearest to the painter?

An 82-kg painter stands on a long horizontal board 1.55 m from one end. This 27-kg board is uniform, 5.5 m long, and supported at each end by vertical posts.

A: What is the magnitude of the total force provided by both posts?

B: What is the magnitude of the force of the post nearest to the painter?

I know to do Part A but I am stuck on Part B. Can someone please help?

2 Answers

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  • Whome
    Lv 7
    2 years ago
    Favorite Answer

    A: What is the magnitude of the total force provided by both posts?

    sum vertical forces to zero

    F - (82 + 27)(9.81) = 0

    F = 1069.29 N

    B: What is the magnitude of the force of the post nearest to the painter?

    sum moments about the support farthest from the painter to zero

    F[5.5] - 82(9.81)[5.5 - 1.55] - 27(9.81)[5.5/2] = 0

    F = 822.88...N

    Round to appropriate precision.

    I hope this helps.

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  • oubaas
    Lv 7
    2 years ago

    Ra+Rb = (82+27)*9.806 = 1069 N

    Ra = (27*5.5/2+82*1.55)*5.5*9.806 = 359 N

    Rb = (27*5.5/2+82*(5-5-1.55))*5.5*9.806 = 710 N

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