Question

What does Newton’s third law states for the conservative forces?

(a) The rate of change of momentum is equal to the force applied

(b) For every reaction there is an opposite reaction

(c) The body is tend to be rotated if the force is applied tangentially

(d) The body is rest until a force is applied

I had been asked this question in quiz.

The doubt is from Conservative Forces in chapter Principle of Virtual Work of Engineering Mechanics

Answer 1

Correct choice is (b) For every reaction there is an opposite reaction

To elaborate: The requirement of the third law is important in the equilibrium of the body. Specially the rigid bodies. The rigid body particles are in the equilibrium and are thus facing the forces and to be in the equilibrium they also react and apply the opposite force and thus the third law of Newton. It is the same for all the methods.