hello everybody, I have a question regarding the fictitious force (d'alembert force) we usually add to an examined body in a noninertial reference system. As I understood from reading and leraning about this topic, this force is artificially added only to compensate for exploring this body in noninertial reference system and that this force doesn't really exist - so the body doesn't actually "feel" it. Now, an interesting case made me think again about it. If I take a cylindrical body and accelerate it abruptly to about 20g (even in a vaccum environment- no aerodynamic effects), this body might go through buckling. When I make a free body diagram of this body in an inertial reference system, the only force that this body undergoes is the thrust force - a single force which accelerates it. For buckling we need to have compression (2 equal and opposing forces on a body), while I mentioned above only a single force. When I explore this body in a noninertial reference system I add d'alembert force, and now it seems to solve the problem - on one hand we have the thrust (+F) force and on the other one we have the d'alembert force (-ma), so the body undergoes compression and buckling is now possible. But, as I was taught - d'alembert force isn't real and can't be treated as a force which physically affects the body. In addition, I would like to find a consistent solution in every reference system, and not only in this private case of exploring a body in a noninertial reference system. By the way, a similar example is the extension of a turbine blade while it rotates. While it rotates in a constant velocity it only has a centripetal force towards the center of rotation (when exploring this body in a noninertial reference system), and still undergoes an extension (as a result of tension)... Thanks Everyone!