Mechanics Corner #50
A Journal of Applied Mechanics and Mathematics by DrD
Why You Should NOT Use the D'Alembert's Principle
I think it is safe to say that every engineering student studies both Statics and Dynamics. We are told that Statics is easier than Dynamics, which is often true but not so in all cases. When we get to Dynamics, many teachers, particularly physics teachers, will urge the use of something called D'Alembert's Principle. They tell us that it reduces dynamics problems to statics problems and thus makes life so much easier. This is a lie! It just is not true!!
For an extended discussion about why this is the case, read on please.