I love the way you teach! Thank you for being an awesome teacher! :D

Thank youuuuuuuuuuu I having searching for this for ages

That's an even better guess. I'm going to let more folks wrestle with it, and I'll clear it all up on Friday if a consensus isn't built by then.

The original equation was for a standing wave, frozen in time. Plugging in the second part for x allows you to analyze a moving wave using the standing wave equation. Subtracting the lambda*t/T term (distance traveled by a point on the wave in a given time) from the current position of a point on the moving wave lets you incorporate time into the equation, without changing the original statement.

i like your approach to the wave equation. it makes more sense than the conventional mathematical approach Well Done!

Feels weird to learn something from someone who sounds like ashton kutcher in that 70´s show!

ahhhh I love you for this vid, it clicked some things for me

Thank you for this video and your explanations.

Thankyouuu.. coz it all makes sense now!

very nice explanation!!!

Thanks for the video Do you have any kind of written source I could refer, when using this in my assignment?

In my text book (t/T-x/lamda) ... is it same or not ?

Well, I don't know why the function has negative sign there in terms of physics. In term of math however, the graph shifts to the right when the value is negative in the bracket like cos(x-2) and vice versa. It's almost as if the axis actually moves along the negative/positive signs but not the graph itself. If I'm to hold the graph in the same place, but move axis by 2 to the left instead, it will be just like how I move the graph to the right by 2.

@DocSchuster

10 жыл бұрын

That's very good!!!

@mattskakun5827

9 жыл бұрын

"if I'm to hold the graph in the same place, but move axis by 2 to the left instead, it will be just like how I move the graph to the right by 2." tuck295q if you moved the graph to the left would it be a positive sign in the equation? Doc Schuster

@justinchai1449

6 жыл бұрын

tuck295q a

According to me reason for that negative sign is that when we are taking out displacement of x in terms of x only then that equation will only give us displacement of particle x only for an instant but according to doc that cos wave is moving forward so displacement of x will be also be varying with time therefore for some unique value of x we subtract the distance travelled by that cos wave in time t to reach back at that position x and to calculate it's current displacement. Correct me by commenting on this if I have said something wrong.

minus sign because the wave is moving to the right and subtracting from the argument moves the graph to the right which gives us a moving wave if the wave would have been moving to the left it would have been positive sign there and the curve would move to the left

Thank you brother

are we supposed to be in radians or in the other mode for all this stuff?

duuuuuuuuuuuuuuuuuuuuuuuuude i love youuuuuuuuuuuuu

Thank you so much mannnnnnnn

i need more leacturs on wave

Hi Doc Schuster. Could you care to explain the negative sign?

Is the reason you use can set up the eqn x(peak)= lambda*t/T because you rearranged the speed = dist/time formula for distance? Or did you use the trig function? I'm little confused as you just jumped in without any reason for using...THanks

@RayanMADAO

8 жыл бұрын

+HAPPYBOY Yeah buddy Think about it, when t = Period(T) then the x(peak) = 1lambda or wavelength. So the position of that peak is one wavelength like you see at the bottom graph

elegant

well, its a minus sign because the angle inside "cosine" is a ratio to the Amplitude, as cos(theta) is between -1 and 1. hence by minusing, the ratio decreases, such that A is now smaller in the next instance. ( i.e. the wave is moving to the right)

@DocSchuster

9 жыл бұрын

dominic chan If a cosine moves right OR left, though, A will decrease at the origin identically. Did I understand your argument correctly?

@xMrTongx

9 жыл бұрын

well, if we keep x a constant, when t increases, the why component of x will just go straight n down, as through a transverse wave has passed through.

Why x(t) - lambda(t/T) was substituted for X ? in the original equation.

I am waiting.

sir can u ellaborate what exactly 2 pi x/lambda

Good try, but it would be negative even for a steady traveling wave. For frictional decay, we'd want to multiply the whole dang thing by a modified version of e^(-bt/2m). It'd be even more interesting if decay depended on position, but that's not a first-year problem, I think. Keep guessing!

why cant the function be just y = asinx , do we introduce a constant for getting rid of any dimensions from the angle?

It is minus because it is a cossine function! The minus signal gives the argument that the function needs!

Thanks I could not find the last equation anywhere

thing I don't understand is from 8:18, (Xsome_other_peak - lamda*t/T)=lamda say, Xsome_other_peak=3lamda, this peak occur at 3T , then 3*Lamda - lamda*3T/T equals ZERO not Lamda.

My sir told that equation of standing waves is either y= A sin (wt) cos kx or A cos(wt) sin kx. Why did you consider only cos?

So if the energy is being transferred from one particle to another why do se say that the mechanical energy of a particle is constant?! And it just changes from kinetic energy to potential energy and vise versa?!

E=1/2 A2 W 2 --> the formula for the energy of particles in SHM ; actually I don’t understand the difference between the energy of the particles and the wave , aren’t they the same ?!

Like u dont even have to ask me/us to like it. We will pause it, like d video and go 10 secs earlier

Aren't lambda and period the same?

@sumanacharya9504

4 жыл бұрын

Nope, Lambda refers to the wavelength of the wave while the period refers to the time duration in which original configuration of peak is restored at that point.

why am i not getting that i want😢😢

Why is it negative? Hmm...

the -ve sign is to rid the answer in terms of nlamda

it'ss a minus because it has to be zero and booth terms are positive

'You' can't keep it.Can 'Your'?i Cann.

Radians are the natural choice. Those Babylonians and their penchant for 60s...dang it.

you don't leave

buy a mcDonalds

don't be like paul