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    Question attached. For a), I called tension on string BC Ta and tension in D and the mass Tb.

    Resolve upwards:
    Tasinα+Tb=600

    Moment around a):
    400(2)+200(3)=Tasinα(4)+Tb(3)
    Which leads to Ta=400root5 when solving simultaneously

    Where have I gone wrong?

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    (Original post by bobbricks)
    Question attached. For a), I called tension on string BC Ta and tension in D and the mass Tb.

    Resolve upwards:
    Tasinα+Tb=600

    Moment around a):
    400(2)+200(3)=Tasinα(4)+Tb(3)
    Which leads to Ta=400root5 when solving simultaneously

    Where have I gone wrong?

    Posted from TSR Mobile
    I get 400(2)+200(3) = 4Tsina by taking moments about the hinge

    then resolving

    Verically
    Y+Tsina = 600

    Horizontally
    X=Tcosa

    where X and Y are the components of reaction at the hinge
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    (Original post by TeeEm)
    I get 400(1.5)+200(2) = 3Tsina by taking moments about the hinge
    I think this should be 400(2) + 200(3) = 4Tsina.
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    (Original post by SherlockHolmes)
    I think this should be 400(2) + 200(3) = 4Tsina.
    possibly
    i might have misread distances

    teaching at the moment and I have no glasses!...
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    (Original post by TeeEm)
    I get 400(2)+200(3) = 4Tsina by taking moments about the hinge

    then resolving

    Verically
    Y+Tsina = 600

    Horizontally
    X=Tcosa

    where X and Y are the components of reaction at the hinge
    Isn't the reaction at the hinge horizontal so no vertical component?

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    (Original post by bobbricks)
    Isn't the reaction at the hinge horizontal so no vertical component?

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    Definitely not!
    Consider what will happen if you take moments about the other end of the rod ...
    What balances the two weights then?
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    (Original post by TeeEm)
    Definitely not!
    Consider what will happen if you take moments about the other end of the rod ...
    What balances the two weights then?
    The vertical component of the string BC (Tsinalpha)?

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    (Original post by bobbricks)
    The vertical component of the string BC (Tsinalpha)?

    Posted from TSR Mobile
    if you take moments about B, the tension has no moment!
    So there is vertical reaction (UP) to balance the 2 weights.
 
 
 
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