A painter stands a horizontal platform which has a mass of 20kg and is 5m long, the platform is suspended by two vertical ropes , one attac

Question

A painter stands a horizontal platform which has a mass of 20kg and is 5m long, the platform is suspended by two vertical ropes , one attached to each end of the platform . the mass of the painter is 70kg . if he is standing 2m from the centre of the platform . Calculate the tension in each of the ropes.​

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Acacia 3 years 2021-08-22T13:58:05+00:00 1 Answers 23 views 0

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    2021-08-22T13:59:24+00:00

    Answer:

    R = 715.4 N

    L =  166.6 N

    Explanation:

    ASSUME the painter is standing right of center

    Let L be the left rope tension

    Let R be the right rope tension

    Sum moments about the left end to zero. Assume CCW moment is positive

    R[5] – 20(9.8)[5/2] – 70(9.8)[5/2 + 2] = 0

    R = 715.4 N

    Sum moments about the right end to zero

    20(9.8)[5/2] + 70(9.8)[5/2 – 2] – L[5] = 0

    L =  166.6 N

    We can verify by summing vertical forces

    116.6 + 715.4 – (70 + 20)(9.8) ?=? 0

                                                 0 = 0  checks

    If the assumption about which side of center the paint stood is incorrect, the only difference would be the values of L and R would be swapped.

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