Question

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

(a) The moment need not to 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

I got this question in class test.

Enquiry is from Frictional Forces on Screws topic in portion Friction of Engineering Mechanics

Answer 1

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

Explanation: The forces in the three force system are 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.