Question

The three force system can also be in the equilibrium if:

(a) All the forces are parallel to each other heading towards the same direction

(b) The force components cancel each other

(c) The forces are very small in magnitude

(d) The forces are very huge in magnitude

The question was asked in an interview for job.

This interesting question is from Characteristics of Dry Friction in chapter Friction of Engineering Mechanics

Answer 1

Right option is (b) The force components cancel each other

To elaborate: Even if the forces components cancels each other than the body is said to be in equilibrium. Also, it should satisfy whether the moments caused by the forces are equal to zero or not. This means that we need to take components of the normal and frictional forces so as to make the desired calculations.