How do we calculate a simple string with a golf ball at one end, pendulum swinging say, 3 feet long hanging from the ceiling starting at an angle of 27 degrees => The time calculation when it HAS ACTUALLY begins to STOP, JUST HANGING THERE STIL?
It seems to me that there is no formal proof or experimental evidence for why the damping force is proportional to velocity. Instead, Engineers just assume F = - c v for the sake of mathematical simplicity. Is this true?
amal hassnaoui This course was for undergraduates. MIT is no longer actively hosting this course. (Here is the reason why: newsoffice.mit.edu/2014/lewin-courses-removed-1208.) You can find the course materials on one our mirrors by searching for "MIT 8.03SC Physics III: Vibrations and Waves, Fall 2012"; and the videos can still be found on the Internet Archive (archive.org/details/MIT8.03F04, archive.org/details/MIT8.03SCF12). Good luck with your studies!
+MIT OpenCourseWare I read your comment yesterday and reverted back now. This is Professor Wit Busza! That is Walter Lewin! Different people! I didn't realize that until now. Reading this news yesterday put my mental state in extreme cognitive dissonance since I have been learning a lot from these videos. Thankfully now I can continue with this playlist perhaps...
at 30:20 he reveals the board with the already worked out solution to weak damping case and on the board on the right hand side, second line, you see the definition of omega prime as 1/2sqrt(4omega_0^2 - \gamma^2), a modified frequency (it appears in the final solution sine function multiplying t, which controls how fast the since function oscillates)
It seems the number of views of these lectures also oscillate with a large damping effect (as you progress from lec 1 - 10)
Let me be a part of impulse that persists in the series at the end. So the decay of conservative energy would not be that sharp
Love from India. What a presentation. We are inspired by your way of teaching. Hats off👌👌
"If I've had a room full of students here that would correct me, Then I could've caught the mistake" XD
WE'RE Sorry professor Wit!!!
chân thành cảm ơn ngài!
impressive teaching
How do we calculate a simple string with a golf ball at one end, pendulum swinging say, 3 feet long hanging from the ceiling starting at an angle of 27 degrees => The time calculation when it HAS ACTUALLY begins to STOP, JUST HANGING THERE STIL?
The pink curve at 27:23 doesn't make much sense, the difference of the two exponential functions should never be bigger than either one. :D
True, but it is qualitatively correct: initially 0, rising to a maximum and then decaying asymptotically back to 0.
True, and the maximum is (angular velocity at t=0)/α2-α1, not (angular velocity at t=0)
It seems to me that there is no formal proof or experimental evidence for why the damping force is proportional to velocity. Instead, Engineers just assume F = - c v for the sake of mathematical simplicity. Is this true?
actually, for small v, F=-cv is a good approximation to experimental data. The complete expression is F=-cv -d*(v^2)
You say this because you can not hear Stephen Hawking
@@xicosim6524 Lewin gave a great demonstration of those two terms in his 8.01 series.
thank you sir...
Hello
Is this course for undergraduate or graduate students?
amal hassnaoui This course was for undergraduates. MIT is no longer actively hosting this course. (Here is the reason why: newsoffice.mit.edu/2014/lewin-courses-removed-1208.) You can find the course materials on one our mirrors by searching for "MIT 8.03SC Physics III: Vibrations and Waves, Fall 2012"; and the videos can still be found on the Internet Archive (archive.org/details/MIT8.03F04, archive.org/details/MIT8.03SCF12). Good luck with your studies!
***** Okey Thank you for your response
+MIT OpenCourseWare I read your comment yesterday and reverted back now.
This is Professor Wit Busza! That is Walter Lewin! Different people!
I didn't realize that until now. Reading this news yesterday put my mental state in extreme cognitive dissonance since I have been learning a lot from these videos.
Thankfully now I can continue with this playlist perhaps...
+Ahmad Shumayal
Yeah, it scared me a little bit whew, thanks.
thank you! :)
I think it should be (ω_0)^2 = 3g/2l
Agreed - which is how he defined it in the previous video and when he later writes the equation b > sqrt(2gl/3)ml he used your correction.
If you're watching before your exam, put it at 1.5x speed
The camera guy is really slow at keeping up with the professor lol
anyone know where the omega prime is from?
Where in the video?
at 30:20 he reveals the board with the already worked out solution to weak damping case and on the board on the right hand side, second line, you see the definition of omega prime as 1/2sqrt(4omega_0^2 - \gamma^2), a modified frequency (it appears in the final solution sine function multiplying t, which controls how fast the since function oscillates)
Whats means gamma
it is a constant related to the drag force. We consider drag force or torque to be equal to -gamma*velocity(or angular velocity in case of torque)
it is called the damping coefficient