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Attached is a picture of the truss. I am trying to calculate the member forces.
I know a moment is = force * perpedicular distance, but in this case, for example, if i am taking moments about A, Would the equation be
-(1*2KN)+(1*c) = 0
or using an alternative perpedicular distance
-(2.4*2KN)+(0.8*c) = 0
For my preliminary working, assuming i have used correct perp distance i have
ƩFx = 0
ƩFy = 0
ƩMoments about a point = 0
Ay + By - 2KN = 0
Momments about A = -(2KN * 2.4) + 1*ReactionC = 0
-4.8KN = reactionC
Sub into first eq
Ay +(-4.8) -2 = 0
Ay = 6.8
To find out the reaction in member AB
I have
6.8 - Tab Cos(tan-10.8/1) = 0
Tab = 6.8/Cos(tan-10.8/1) = 8.738
I have the answer to be 2.56
I know a moment is = force * perpedicular distance, but in this case, for example, if i am taking moments about A, Would the equation be
-(1*2KN)+(1*c) = 0
or using an alternative perpedicular distance
-(2.4*2KN)+(0.8*c) = 0
For my preliminary working, assuming i have used correct perp distance i have
ƩFx = 0
ƩFy = 0
ƩMoments about a point = 0
Ay + By - 2KN = 0
Momments about A = -(2KN * 2.4) + 1*ReactionC = 0
-4.8KN = reactionC
Sub into first eq
Ay +(-4.8) -2 = 0
Ay = 6.8
To find out the reaction in member AB
I have
6.8 - Tab Cos(tan-10.8/1) = 0
Tab = 6.8/Cos(tan-10.8/1) = 8.738
I have the answer to be 2.56
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