Question

If all the reactive forces are intersecting at the common point or pass through a common axis when _____________

(a) The body is in equilibrium

(b) The body is said to be achieve stability but no equilibrium

(c) The body is said to be improperly constrained

(d) The body is in deformation

This question was addressed to me in an interview for job.

The origin of the question is Constraints and Statical Determinacy in section Equilibrium of a Rigid Body of Engineering Mechanics

Answer 1

Correct choice is (c) The body is said to be improperly constrained

For explanation I would say: If all the reactive forces are intersecting at the common point or pass through a common axis then the body is said to be improperly constrained. Whether it may be the reactive forces being parallel. Or be it the forces meeting at a common point. The body is said to be improperly constrained.