D’Alembert’s Principle of Virtual Work | Active Forces & Workless Constraint Forces | Lecture 18

[@naderzamani5752]

Wonderful lectures. Thank you.

[@mrwayofwarrior7853]

Great virtual work deserves a great virtual like.

[@fcvgarcia]

Thanks for sharing, Dr. Shane. What a great explanation!!!

[@abdullahsonde6296]

Hello professor, can u please let me known which book are you referring?

[@ProfessorRoss]

► Textbook: Engineering Dynamics: A Comprehensive Introduction by N. Jeremy Kasdin and Derek A. Paley press.princeton.edu/books/hardcover/9780691135373/engineering-dynamics (from the video description)

[@abdullahsonde6296]

@@ProfessorRoss thanks alot professor ❤️

[@sudipsarkar3172]

I have a question...is sliding friction a constraint force?

[@ProfessorRoss]

No. It would show up as a generalized force Q_i. I discuss friction in this video kzbin.info/www/bejne/fpXRiY2ArpyWl6s

[@hdheuejhzbsnnaj]

You will have many views soon.

[@dataar7441]

How did we find d v/ dt

[@ProfessorRoss]

What part of the lecture specifically are you asking about?

[@dataar7441]

@@ProfessorRoss 59:00

[@ProfessorRoss]

It was derived in an earlier lecture, here kzbin.info/www/bejne/qJ2YdqiqmN6jodk

[@johnniefujita]

goldstein right?!

[@ProfessorRoss]

I learned from Goldstein as a physics major, but I now teach from Kasdin and Paley: press.princeton.edu/books/hardcover/9780691135373/engineering-dynamics

[@abcdef2069]

D’Alembert principle is a principle to waste of your brain energy for years with a fancy delta notation to something so obvious, why would i even mathematically care the possibility of the motion going through a blocking wall, since it is blocked, lets just move to the unblocked way. for a circular motion, if the string is a constraint for the centripetal force, the string will exert a micro tug towards it, this micro tug produces a centrifugal force that is inertial force, some might say this force is a fictitious, an imaginary or an rotational coor force, but i would never call it fictitious or imaginary which is a big mistake and misleading. i would call it a non inertial or a rotational or an inertial force. F = Ffixed + Ffictitious is misleading. but it should be called F = Ffixed + Frot or F = Ffixed + Fnon-inertial