Question

What is after taking the assumption of the direction of the force, the direction comes opposite?

(a) The assumption made was wrong and the question can’t be solved further

(b) The assumptions are not to be taken

(c) The direction is in the opposite sense, and hence the direction is known to us

(d) The direction will be already given to us, no need of assuming

I have been asked this question during an online exam.

This key question is from Method of Joints topic in section Structural Analysis of Engineering Mechanics

Answer 1

Right choice is (c) The direction is in the opposite sense, and hence the direction is known to us

For explanation: The direction is comes opposite, means that the assumption was wrong. But that doesn’t means that the question can’t be solved further. One needs to change the sign of the direction and the question is solved. Thus the calculations of the force direction.