lundoi

Its going to be 2023 in some days these lectures are evergreen

Damn i was born in 2004

U mean 2024

Bhaiya aap quora use karte ho?

fellow IIT-ian, and i 100% agree with you. This lecture helped me understand the concept so clearly, it's never getting out of my head again!

Does this really comes in engineering!!! I am studying this for getting into IIT

@@dhruvpatel4773 Keep in mind that MIT is only a very mediocre University. That's why only 101 people who studied at MIT or who lectured there received a Nobel Prize. *That's very embarrassing.* Luckily you got a much better education.

@@lecturesbywalterlewin.they9259 oh sir.. you replied. But MIT is best university in world according to rankings. Even topper of NEET and JEE prefer MIT over other colleges. I don't know in dept about noble prices but 101 is very big number for me. I was socked to see your reply 🥴

kzfaq.info/get/bejne/e7NnmJyTnbK-cmw.html kzfaq.info/get/bejne/fc6RqtqJyLfXhac.html

Wasn't expecting an answer, amazing, thanks for sharing I'll check them out!

@@lecturesbywalterlewin.they9259 This has turned into an addictive habit. Whenever I get to write on a chalkboard I always try to find a way to do this trick.

:)

you are very welcome

:)

Live long and prosper.

:)

Yeah right 😅

Thank you so much 😀

very true

@@lecturesbywalterlewin.they9259 you killed it

Glad you enjoyed it!

omg!

You are most welcome

You are very welcome

how many minutes into the lecture?

38:35 minutes in (when you slightly alter the amplitude formula to suit the pendulum). Thank you.

I watched from 37:30 - 39:15 and I do not understand your question. *I then watched from **30:00** to **45:00** and I cannot add to the clarity of this lecture.* I suggest you watch it again

Yes, it is more of an extension; I am writing a paper on how pendulum length impacts it’s amplitude during resonance. The equation shown at 38:37 suggests that as you increase the length of the pendulum (decrease omega zero), the amplitude, at resonance DECREASES. This didn’t seem to make sense for me, as I mentioned above, because I would have thought that increasing length, would increase pendulum amplitude (x distance from origin, x=0). Thank you

Perhaps I can make my question simpler: what units is the pendulum Amplitude in (meters or degrees?) Thank you

The answers are in my lecture

@@lecturesbywalterlewin.they9259 hahahaha

if it helps you OK - it's not accurate though

Most welcome

same at MIT. I often ask questions like *who thinks it will increase? some students raise their hands * who thinks it will decrease? * who thinks it will stay the same I often ask questions that I want them to think about at home

They are simply dumbfounded by the brilliance of the lecture! I strongly wish that I had such teachers for all my subjects in high school and college. A proper understanding can ignite a person's creativity.

I mention this in my 8.01 lecture on resonance + Tacoma Bridge

Thanks

because of the Euler expansion......cost+i.sint (basically to avoid complexity)

You can always choose a frequency, but your solution will then have a transient component which wil ultimately die out and after that you will have the steady state solution. .

only the real part of e^iwt gives you the magnitude and that's the cos

try it

talk my math with your math teacher

yes Q is called the "quality"

>>>will be the same as the amplitude of the driving component (F0/m)>>> how many minutes into the lecture?

The most general soln must contain a phase angle. Just like the most general soln for F=-kx must contain a phase angle. If you leave this out, in general you will not be able to meet the initial conditions.

homework assignments and exams of 8.03 are posted below the video thumb nails

Thank you! I never noticed that before! Much appreciated.

most college physics books cover this subject in the same way. 8.03 Vibrations and Waves by Anthony French CRC Press ISBN 9780748744473 8.03 Electromagnetic Vibrations, Waves and Radiation by Bekefi and Barrett. The MIT Press ISBN 0-262-52047-8

thank you sir

Vibration and waves A.p. frech

I cannot add to the clarity of this lecture

the metronome oscillates at its resonance freqs.

yes, but their amplitudes are kept relatively the same as the starting amplitude. Originally they should very soon stop because of the damping, but now they can usually last for about 15minutes. Then the escapement must be driving the metronome from stopping no?

quality

At 24 mins

I watched at 30:14. My lecture is x-tal clear, I cannot add to it.

I know this but I cannot fix it. On one day, out of the blue, I noticed that lect 3 of 8.03 was missing. I have no idea how that happened. Luckily I could link it to the version in "For the Allure of Physics".

how many minutes into the lecture?

sir, in current lecture from 53.03 to 53.35 min, and in 8.01( lecture 31), from10.22 to 10.30 min

you have to be a bit patient and wait till transient phenomena have died out. At 53:40 the two are perfectly out of phase. No need for me to look at 10:30.

Double differentiate to check maxima or minima

8.01 Physics Hans C. Ohanian Physics Volume 1 2nd edition W.W. Norton & Company ISBN 0-393-95748-9 8.02 Physics for Scientists & Engineers by Douglas C. Giancoli. Prentice Hall Third Edition ISBN 0-13-021517-18 8.03 Vibrations and Waves by Anthony French CRC Press ISBN 9780748744473 8.03 Electromagnetic Vibrations, Waves and Radiation by Bekefi and Barrett. The MIT Press ISBN 0-262-52047-8 ---

we know it is steady state because you made the assumption that t->infinity the moment you wrote down that the angular frequency of the solution z has the same w as the driver, correct?

The steady state solution of an oscillator driven with frequency omega will ALWAYS be omega.

Do you know India?Then come to India to teach.

at 11:49 everything on the black board is correct.

Ohhhh, I've found my mistake. Thanks.

I watched at 1:04:44. Have you ever watched a movie where a car goes forward but the wheels rotate backwards? That's a beat phenomemon between the frequency of the images (1 image every 1/16 of a sec) and the motion of the wheel. I have a record palayer. It comes with a disc with black lines on it. You place the disk on the rotating table and you use flurescent light (fixed frequency 50 Hz or 60 Hz). You can now adjust the rotation speed of the turn table so that the black lines stand stil. *That too is a beat phenomenon.*

@@lecturesbywalterlewin.they9259 Not at all Intitutive 😅.

how many minutes into the lecture?

33:11

it's not a circular motion

yes e^(jwt)= cos(ωt) + jsin(ωt) I suggest you keep the sin term in your eqs. Near the end the result must be real and that's where you end up only with the cos term

@@lecturesbywalterlewin.they9259 ohhh . Thank you so much sir :D , I'll rework the whole thing !

You solve the differential equation in the form of the following. m*x" + k*x = 0 You start by making the assumption that x has the form of C*e^(r*t), where r is a constant that can be real or complex, and where C is an unknown constant. You'll get two solutions for r, and you then form a linear combination of the two. When you differentiate it at its various degrees, you get the following: (m*r^2 + k)*e^(r*t) = 0 You then solve a quadratic formula to get that r = +/- j*sqrt(k/m), which we'll call j*ω. Now you use Euler's formula to substitute back into the exponential function: e^(j*ω*t) = cos(ω*t) + j*sin(ω*t) And we construct a linear combination of both values of r: x = C1*e^(+j*ω*t) + C2*e^(-j*ω*t) By letting C1 and C2 be complex numbers, we can show that this is a linear combination of sine and cosine. Those complex numbers are: C1 = 1/2*(A - B*j) and C2 = 1/2*(A + B*j) Substitute C1 and C2 into the previous expression for x, and expand with Euler's formula. When we are finished, the complex coefficients will cancel, and we will be left with a linear combination of sine and cosine, where A and B are the respective amplitudes of the component functions: x = A*cos(ω*t) + B*sin(ω*t)

We can write x(t) in the form of a linear combination of two trig functions: x = A*cos(ω*t) + B*sin(ω*t) And we can also write it in the form of a single amplitude trig function and a phase offset: x = x0*cos(ω*t + φ) With trig identities, you can show how x0 and φ relate to A and B.

question unclear.