Question

For the conditions of the equilibrium of the body, i.e. the rigid body only the external forces defines the equilibrium. And the support reactions only cancels out the rotation part of the body.

(a) The first part of the statement is false and other part is true

(b) The first part of the statement is false and other part is false too

(c) The first part of the statement is true and other part is false

(d) The first part of the statement is true and other part is true too

The question was posed to me in unit test.

My enquiry is from Conditions for a Rigid-Body Equilibrium topic in portion Equilibrium of a Rigid Body of Engineering Mechanics

Answer 1

The correct answer is (c) The first part of the statement is true and other part is false

For explanation: The application of the support reaction forces does affect the conditions of the equilibrium of the body. Not only the external but the support reaction forces that are developed by the sake of external forces does develop a tending effect on the equilibrium of the body. Thus the support reaction forces also cancels the external forces.