Question

Which of the following statement for the three force system is true?

(a) The moment need not be seen for the equilibrium, they are always in equilibrium

(b) The forces are not always in the equilibrium

(c) The forces are always in equilibrium

(d) The moments are always in equilibrium

The question was posed to me during an online exam.

Question is taken from Two and Three Force Members in division Equilibrium of a Rigid Body of Engineering Mechanics

Answer 1

The correct answer is (b) The forces are not always in the equilibrium

The explanation is: The forces in the three force system is not always in the equilibrium. The equilibrium is established when the forces cancel out each other. Also when the net moment is zero. Then only the equilibrium is established in the three force system.