Physics is theoretical knowledge, while Engineering (mechanics) is practical knowledge. Physics is great on it's own, and so is Engineering. But when you combine the two of them, they can make MIRACLES! read more
Mechanics is a subset of Physics. Physics is the the use of mathematics to study, model, and predict phenomena in the observable universe. Mechanics is the branch of physics which has to do with motion, mass, acceleration and force. Often, as a shorthand, mechanics is referred to as 'Newtonian Mechanics' or 'Classical Mechanics'. read more
The difference between quantum physics and classical physics is that classical physics only works within a certain range of phenomena. Typically, when one starts talking about things that go on at the level of photons and electrons classical physics no longer gives reliable answers. read more
Quantum mechanics (QM – also known as quantum physics, or quantum theory) is a branch of physics which deals with physical phenomena at microscopic scales, where the action is on the order of the Planck constant. Quantum mechanics departs from classical mechanics primarily at the quantum realm of atomic and subatomic length scales. read more