Question

D-Alembert’s principle is used for which of the following?

(a) Change static problem into a dynamic problem

(b) Change dynamic problem to static problem

(c) To calculate moment of inertia of rigid bodies

(d) To calculate angular momentum of a system of masses

I had been asked this question during an interview for a job.

My question is from Resultant Effect of a System of Forces Acting on a Rigid Body in portion Inertia Forces in Reciprocating Parts of Machine Dynamics

Answer 1

The correct answer is (b) Change dynamic problem to static problem

To elaborate: D-Alembert’s principle states that the resultant force acting on a body together with the reversed effective force (or inertia force), are in equilibrium. This principle is used to reduce a dynamic problem into an equivalent static problem.