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<p>That depends on what you mean by “useful”, of course. Most would argue that pure physics is not useful outside of a purely academic sense (which I personally still consider useful). Applied mechanics is somewhere between physics and engineering, so most would argue that its practicality is somewhat greater than that of physics.</p>
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<p>This is just silly. For starters, mechanics is a branch of physics that is just as relevant now as it was in the 1700’s. It is plenty modern. There are numerous unsolved challenges left in mechanics, a good example of which is the transition to turbulence in a fluid flow.</p>