Question

What is after taking the assumption of the direction of the force in space trusses, 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 got this question in my homework.

The above asked question is from Space Trusses in chapter Structural Analysis of Engineering Mechanics

Answer 1

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

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.