Compare and contrast between D'alembert's principle with principle of conservation of energy?
Answers
Basically D'alembert principle can be stated that the sum of the Energies at a junction is zero For example in a beam the sum of the Energies bearing down on a beam is equal to the Sum of the reaction energies to the beam. Hence the sum of the energies relative to the beam is zero. which is basically another way of stating newton 3rd law of motion.Where an action is equal to the reaction. The laws of conservation energy applies only to a conservative system where Power can be transferred between systems without any energy loss to outside the system.
D'Alembert's principle, also known as the Lagrange–d'Alembert principle, is a statement of the fundamental classical laws of motion. It is the principle of virtual work for applied forces in a static system avoiding restriction to masses. It does not depend on the velocities. If the negative terms in accelerations are recognized as inertial forces, the statement of d'Alembert's principle does not apply for irreversible displacements, such as sliding friction, and more general rules of the irreversibility constant.
The principle tells that the summision of the differences of the forces that act on mass and the derivatives of the momentum of the system is zero