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 and thus the potential energy of the body is stored in it.

(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

This question was posed to me in exam.

My question comes from Potential Energy topic in division Principle of Virtual Work of Engineering Mechanics

Answer 1

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

Best 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.