Hi all, I'm doing some last minute revision for a mechanics test, and I'm going through a practice paper. I'm stuck on one question about mechanical frameworks. Here is a picture of the framework:(adsbygoogle = window.adsbygoogle || []).push({});

(It seems I can't display the image directly in my post on this forum)

The problem is to calculate the force, and identify the type of force (tensile or compressive) in each member of the framework. Heres what I've done so far:

Calculated the reaction forces:

Resolving vertically:

4kN+3kN+5kN=R[tex]_{R}[/tex]+R[tex]_{R}[/tex]

R[tex]_{R}[/tex]+R[tex]_{R}[/tex]=12kN

taking moments about L (where R_L is acting):

-4k*2-3k*4-5k*6+R[tex]_{R}[/tex]*8 = 0

R[tex]_{R}[/tex]*8 = 50kNm

R[tex]_{R}[/tex] = 50k/8 = 6.25kN

R[tex]_{L}[/tex]= 12k - R[tex]_{R}[/tex] = 12k - 6.25k = 5.75k

From this point I'm not sure how to proceed and find the value and type, of the force in each meber of the framework. (9 members)

From the two angles given (30') I can calculate all the rest of the angles in the framework, but I'm not sure it thata helps anything.

Really appreciate some help, thanks alot.

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# Mechanical framework

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