Good walkthrough! Helped a lot! I was wondering why you do not include the 20 and 30kg forces when calculating the moment about G? I thought it might have something to do with the method of sections, but you included them when doing the moment about A, so I'm confused why they weren't used for G. Thanks!
Downward forces? You mean at joints E and F? Neither would have a downward component? In fact, I'm fairly certain they are zero-force members as the roller at G can only exert a normal force FGy, and this upwards exertion is not affected by either F or E as there is no downwards load (force) on them. When you're using the right side of the structure after splitting it and using the moment arm about D, you don't need to compute E and F; just measure from moment D to G.
Thank you @FinalAnswer for providing a crystal clear approach. Helped me to revise the concept through the question.
love your explanations ,tyvm
your the best bro keep it up BTW which country are you from.
Would KD be in compression?
How do you get the phi tan -¹ 3/2 = 56.3°??
Good walkthrough! Helped a lot! I was wondering why you do not include the 20 and 30kg forces when calculating the moment about G? I thought it might have something to do with the method of sections, but you included them when doing the moment about A, so I'm confused why they weren't used for G. Thanks!
I think when u calculate the support reactions all external forces in the system must be included.
When he's doing moment at A, he was looking at the entire diagram. When he was doing moment at G, he was looking at the section cut only
When you do the moment around G, why is it JK*3? and not JK*6?
m=fd, the force should be perpendicular to the distance, thus in this case the perpendicular for the force JK is 3.
Jk is a horizontal force so the perpendicular distance is vertical ..I know it's too late but thanks for this question
Can you solve the problem and extract FH
goodnight.. why did you not use any downward forces at E and F....please tell me ASAP
Downward forces? You mean at joints E and F? Neither would have a downward component? In fact, I'm fairly certain they are zero-force members as the roller at G can only exert a normal force FGy, and this upwards exertion is not affected by either F or E as there is no downwards load (force) on them. When you're using the right side of the structure after splitting it and using the moment arm about D, you don't need to compute E and F; just measure from moment D to G.
I didn't get this one. Where did u get value of 8 in moment equation for point G. Can u explain it, plz
Thank u) i just didn't c the minus sign b4 8
hi, could you please do the problem no.39 in the 14th edition, which is to determine the force in members BC, HC and HG, thanks!
yeah I'll add it to my list!
why cant g have an x force like a could?
5:50 i dont understand how you can just flip the answer? how do you know it was wrong?
if the answer comes out as negative, it's wrong. You need to flip the sign as well as the direction you previously draw in the diagram
How did you get the value of the fy=33.33?
Also my question:(
Me salvaste
how u get KD = 8KNT, cus i try i cant get the answer
the θ is 56.3°, so it must be -40 + 33.33 + KD.sin 56.3° = 0, and KD will be 8.01727 = 8
make sure your calculator is set to degrees