@@muhammadazeemkhan1762 I’ll set up a Teams meeting soon. Let me have your available times as per UK time for next week. I’ll invite for a 15 min Teams meeting.
At 8:03 if all members on the top be in tension how do you get 0 force of the horizontal member left of the second load applied. The reasoning you said was 0 because no horizontal load applied, why can’t the same reasoning be used on the horizontal members next to the first applied load then they should be 0 according to that reason. I think the answer may be C which suits your first point members on the top will be subjected to tension in a cantilever.
As two diagonal members have zero force at the second loaded joint, this leaves us with two horizontal members (one on right of the joint which is zero and the one the left have to zero too for horizontal equilibrium). That is the reason the force is zero on left of the second loaded joint.
C is incorrect because the diagonal members at second loaded joint are zero. Then we only have two horizontal members, the one left is tension and the one right is zero. This is not possible if we have to maintain horizontal equilibrium. When one two horizontal members are connected to the joint, they have to be equal and take the same type of loading, either tension, compression or zero force. That is why the force in the left horizontal member have to be zero for horizontal equilibrium.
The situation at other two top horizontal members is difficult because they are connected with tension diagonals and when we resolve theses diagonal into horizontal and vertical components, the horizontal component is in tension and that is the reason the force in top two left horizontal members is tension. As the answers are very close to each other, I got it wrong myself on my first attempt and chose C, which is the wrong answer.
