*Suggestion:* Intuitive Video on CALCULUS (because the teachers in school just make the students *rote memorize* the 'rules')

@dityaharpatipraja4442

Жыл бұрын

exactly

@Mahesh_Shenoy

Жыл бұрын

I have been meaning to do this from some time now! Will do it next

@GodSahil

Жыл бұрын

@@Mahesh_Shenoy Ye! thanks a ton!♥

@alexandrekassiantchouk1632

6 ай бұрын

Forget 1st Newton's law? BTW, do you know that 3rd law and thus momentum conservation does not hold true in systems with variable time. It works only within Newton's "Absolute time".

@GodSahil

6 ай бұрын

@@alexandrekassiantchouk1632 where that coming from, in my calculus comment section?

The average of a constant set of values is the constant itself. When teaching this formula it’s specified that it is for a constant and or average speed.

It gets interesting. What is speed a property of? Speed can not be a property of an object because speed is relative to the observer. So speed must be a property of relative motion, not the object. But what is motion? And how can motion have an instantaneous speed, what is an "instant"? If there are fundamental limits to scale, how could then the limit we know from calculus "exist" in the "real world"? And if there is such a thing as "instant", what is it? A frozen moment in time? But what does then speed mean in an instant, how could there be motion in a frozen moment in time? Maybe motion happens like pixels changing on the screen? But then how does motion remember its speed between the frames? Motion does not exist in any of the frames, so what is then speed the property of, something outside the frames? So the discrete theory can not be a complete theory of motion, but neither is calculus. Now I am confused, thanks a lot! :)

@fernandocacciola126

6 ай бұрын

Well, just go back to ancient Greece and ask Zeno, he'll clarify your confusion (or not) 😁 (en.wikipedia.org/wiki/Zeno%27s_paradoxes)

@kecskemetib

6 ай бұрын

@@fernandocacciola126 haha ok I would love to ask Zeno about it and time travel sounds like a lot of fun :) btw Feynman mentions this topic briefly in this lecture: kzread.info/dash/bejne/X2aC0NOuqMe9ds4.html

@manomishra

5 ай бұрын

You have raised many points originally talked about in Madhyamika Karika by Nagarjuna. Have you read that it somehow you asked all these on your own. If it is the latter, very impressive.

this is something that wasnt taught to me, but i figured it on my own..(not boasting)..and so its good that these thoughts are getting out there, and students finally start to think

@Kevinjoy2305

4 ай бұрын

So did i, took me a while to confirm that it's avg speed on my own in 9th

My son is in year 11 so they have distance-time and speed-time graphs in maths and physics. The use of words are so much more accurate compared to our time, our education system. They usually work with graohs which clearly show how the object has moved at different time intervals. If they use total distance and total time, then they make sure they use the word 'average' speed. Great educational videos, thanks 👍🏻

The way I learned, so long ago ... Speed = change in distance divided by change in time. Distance and time are both relative

@Krokodil986

2 ай бұрын

In other words differentiating "distance" with respect to time, but how can you speak about these infinitesimally small increments in time? If these increments were limits as change in time tends to 0s, then how can motion exist in a "frozen frame" - motion needs time to exist right?

hi! i'm taking physics in a language i barely understand 🥲, and so i miss lots of explanations, real-life examples, fun facts, concepts, etc. whenever i'm in class, and i just turn to youtube to learn by myself. your videos help a lot with clearing the misconceptions i have, and also providing examples :) so thank you! 🙏

Google Maps does not work out the average speed to then give you the time for a journey. Google Maps uses two algorithms, Dijkstra’s algorithm and A algorithm* to find a set of shortest paths. Traffic flow is then superimposed on those paths. The sum of the times for each section is modified by a temporal variation factor to give you the total travel time. The average speed is never calculated because using that in the methodology was found to be less accurate.

@Krokodil986

2 ай бұрын

That's cool but i don't think Maps uses Dijkstra's since getting an answer from it would take (probably) days

I want to add something to this... Avg speed can also be represented as duration/distance provided the unit is written properly and for convenience of not using decimals, we choose distance/duration

Google maps does work the way suggested at all. It is a complex algorithm, it does not use the average speed for the journey. The times for each section are weighted by variations in time. I think you need to correct that.

Another great and a simple video thank your work and keep going you are amazing I don't think i have ever seen a teacher who actually understand what his doing and trys to make his student understand it with logic and exempls other than you Looking forward for more amazing videos like this

Thank you very much ! I really love your videos, it explains things fundamentally, physics should always be reached that way, fundamentally !

In the absence of further information (such as varying acceleration) the speed is average speed.

Please never stop making videos. Your videos are making me want to go back 10 years to class 11 and study physics again.

I think what you meant to say at the end there is that SPEED is the AVERAGE DISTANCE OVER TIME. My Calculus instructor use to tell us that if you had sufficient data points of your speed throughout the entire trip, you could create an equation that you could then take a derivative of at any point in time and know what you speed was at that point in time ... but he never actually went through the exercise of doing that (creating such an equation) ... I'd like to see that done sometime.

we actually find it out by ourself and we feel the joy of stepping into the unknown by ourself without an explaination. I think we need that as a science student early on

Now I understand why momentum is more fundamental than velocity. Thanks Mahesh. :)

yeh! something related to class 11th finally!

thanks, I wonder about this problem for a long time but didn't get the result until I met your video here.

This is exactly how to make a mountain out of a molehill, that too smiling.

Sarcasm, can you please explain why this word exist in your personality .

Wow! Thanks a bunch for sharing

You have a great mind sir. Keep doing what you are doing. You provide enlightenment and a good vibe.. Thank you

Even calculating “instant” speed is actually an average speed, but the average is over a very short duration (shorter than anyone cares about).

*sigh* Ok. In standard English, when we say " the speed something is travelling at" we are referring to the AVERAGE speed, not the instantial speed. Even the speed on the speedometer isn't a "real" speed since it's basically an estimate based off a spinning wire driven by the wheel. This is a semantic argument and it's silly.

Very good point indeed!. I often wonder if isn't it a mistake that the "calculus mindset" isn't taught right from the start. Here for example, if the car happened to had travelled really really fast for 4 hr 55 minutes, then slow down to almost zero for the final 5 minutes, the Avg Speed so calculated would be arithmetically correct but completely misleading and the ETA would be all wrong. But, if you approached this in the form of "a special sum" (the integral) of the sequence of instant speeds (the differential), then it would become quite evident even for a kid that you need to ignore the "outliers" to get to a more realistic avg speed.

Thanks for your videos. Special kudo for the ones about light momentum and electron spin btw. On that one, we can consider the instant speed to be the limit of average speed for infinitely small time intervals, right ? Speed is still, dimentionally speaking, distance/time. Repeating the process of dividing distance over smaller and smaller time intervals doesn't change that, right ?

@Mahesh_Shenoy

8 ай бұрын

Yes!

Depends on whether you are an observer passing by at close to C. Then we have length contraction to consider... What is the distance travelled relative to the observer?

Hi, I'm following your videos for couple of years now. I was wandering which software do you use for writing and small animations?

The weird thing is that I also pictured that speedometer. However I think it as if it is not changing.

Mahesh, I have been helping my high school aged kids with maths. The mathematics department seem to reflect your concerns. Here is one of the questions… A car travels a 10 km section of Highway with cruise control engaged. Decide on a speed that this car will maintain, and show working to calculate the time it will take at that speed to complete the 10km section of its journey. This question allowed the student to decide the speed, which is a clever way to engage the students, and only mentioned a “section” of the journey. At the time I thought it was a bit weird, but I think it was setting the students up to later calculate the acceleration at the beginning and deceleration at the end of the journey, rather than just averaging everything out. Hope that makes sense, and I think your concerns are valid and others have the same concerns. (Edited to correct spelling of your name).

exactly....it's difficult to unlearn

😫. ITS CRAZY HOW RANDOMLY I FOUND THIS KZread CHANNEL AND REALISE HOW UNDERRATED TVIS CHANNEL IS! I WAS WATCHING THE NEWTON'S SECOND LAW VIDEO FROM MANOCHA ACADEMY AND FOUND THIS GUY'S COMMENT. EVEN WHERE HE IS PROVING PHYSICS 😫 DAMN SIR YOU ARE A REAL PHYSICS GEM 🔥💀

Instant speed is also distance by time - you just take an extremely small time interval - where speed is practically uniform. When tike interval is larger - there is no meaning of instance speed but average means something. In both cases - speed is distance by time.

If space and time were the same thing, I would be 5 feet old and 45 years tall.

Sir, can you please make a video on this strange fact that when the whole slinky falls under the action of the gravity, why the bottom of slinky freezed until the rest of the spring approach the bottom first and then whole slinky falls down. I am still not getting the best explanation from the sources. I will be thankful to you.

Sir can you please share your learning methods and tricks please

It's nice that indian Keegan-Michael Key teaches physics

I think someone got a speeding ticket recently and wanted to get this out in the ether

Mahesh, I am a big fan of your Presentation skill and explaining a concept from multiple point of views. But a point here: The instant speed shown in car (suppose 80) is also dist/time. That is, if I drive with the pointer or needle always on 80 for one hour, I will cover 80 kms of distance. What do you say?

@user-lf5ru9cz3p

3 ай бұрын

Hmm something interesting you are saying I think it is true😮😮😊

In special relativity, this is an approximation. Would be interesting to see more about this, and how the addition of speed formula is derived...

Those of us who teach physics say, "Average Speed = Distance over time." So I have no idea where you got that equation.

1:59 it all depends if the car was driven by the turtle 🐢 or by the bunny 🐰

Average speed = distance/time Fixed it

And how would i figure out my speed if my car was at rest and the landscape was probably moving :)

We all know that your "speed" can be bought on a street corner.

Can you explain the potential difference across a capacitor?

@carultch

7 ай бұрын

Potential's full name is electric potential, which is defined as the electric potential energy per unit charge, at any given point in space. The other charges set up an electric field, and the electric field is a conservative field (assuming magnetism is negligible, which is a topic for another day). Conservative means that the net work done by the force field as a charge follows a closed path is zero, and that the work the field does, is independent of path. Because of this, we can define a potential function, that keeps track of the energy as a function of position, that any given charge has by virtue of its location. That potential function, is called electric potential, or informally, Voltage. Find the potential function at the positive plate of the capacitor, and the potential function at the negative plate. Subtract one from the other, and that tells you the potential difference. This is the work per unit charge that it takes to move an electron to the negative plate and add to the charge of the capacitor. Or, in reverse, the work the capacitor does per unit charge, as an electron moves from the negative plate to the positive plate. Since a capacitor is an insulative gap, the electron doesn't cross the gap directly. Instead, it takes a path through the rest of the circuit. Most likely, a different electron takes its place on the other side, since there are billions of electrons in even our smallest circuits, and it takes months for an individual electron to be likely to complete a closed path.

@kaamesh7973

7 ай бұрын

Thank you for the explanation.@@carultch

Well if our speedometers read in Joules at least then everyone would slow down.

Kids may easily imagine the 100km problem and realise that you don't instantly start at 20km/h, so, as a teacher it may be best to adress this. But this may lead into an hour long meander on the concept of average.

Crucial difference between differential n integral

what happens when we join a conducting wire to a battery? how does the current remains constant? Is this related to transiants?

@carultch

7 ай бұрын

Even a circuit with a resistance, is ultimately an LR circuit with both an inductance and a resistance. Even just a single loop of a circuit inevitably has some unintended inductance, we just neglect it most of the time. The current really isn't constant, but it is an exponential approach function that starts out at zero, and approaches a steady state value. The current vs time follows an equation in the form of V/R*(e^(-R/L*t)). For most practical purposes, that steady state value, is what we consider the current of a circuit. The differential equation is like a falling body with drag. It initially starts with constant acceleration when only gravity and inertia govern its motion, but it asymptotically approaches its terminal speed in the long run. Eventually, the speed increases up to a point where the drag force opposes the force of gravity, and it can no longer gain speed beyond that value. It's an exponential approach, in the form of C*(1 - e^(-k*t)), where C is the terminal speed, and k is a constant that depends on all of the factors.

if you dont love him... you dont have a heart for science !!

None of this makes sense without vectors and differential calculus. Of course we cannot explain kids kinematics at school when they dont speak the language of it.

Mahesh, I have a video idea that might interest you on explaining the Heisenberg uncertainty principal in simple terms. It's related to this video and why I don't believe you can ever truly know instantaneous speed. The calculated speed of anything is *always* an average speed from point A to point B, regardless of distance between those points. Speed *IS* distance over time. You can't have speed without distance. Distance can be defined as the space between 2 points. Therefore you can never ever EVER know true instantaneous speed because it will ALWAYS require TWO points of distance, to be calculated. (yes, I'm shouting). Using a car as an analogy we can observe how long it took to travel across the country and calculate a very precise average speed for the journey, but we have no idea *where* the car is (it's somewhere between the two sides of the country). Alternatively, we can calculate to know *where* the car is by zooming in on its location. When we zoom in, we have a precise location, but the speed we observe is very imprecise relative to how long it truly takes to go across the country. Put this example in an animated video and BOOM - Heisenberg uncertainty principal explained for everyone. Thanks for what you do!

@Mahesh_Shenoy

5 ай бұрын

The explanation feels great, but is unfortunately wrong. Sorry! If you give me the position function of a moving object, I can tell you it's speed (acceleration, and all other higher derivatives) EXACTLY! [Alternatively, if you graph the position function, you can always PRECISELY find the slope of the graph at A SPECIFIC POINT :)] The uncertainty principle is a purely quantum mechanical phenomena arising from the fact that quantum particles have an associated wave function. Remember Feynman's words - “The first principle is not to fool yourself - and you are the easiest person to fool.” Good luck. And thank you!

@entertainme121

5 ай бұрын

@@Mahesh_Shenoy I'm not formally educated. All I know for *sure* is that calculated speed is ALWAYS an average, given that it requires the distance between 2 points to calculate. Yes, yes, you can infer an apparent precise speed using a graph with function plotted, but you'll never "truly" know the precise speed. Likewise, you'll never truly know the precise (1 point) location without forfeiting all information on its speed. It's one or the other. Just as the uncertainty principal states. I think the car analogy is good (or at least, helpful). I'm very sad now. But thank you, none the less.

@entertainme121

5 ай бұрын

@@Mahesh_Shenoy The most accurate measurement of speed we could theorize is the AVERAGE time it takes to go from one end of a Planck length to the other. What exactly happens between those 2 points, only God knows. Maybe the world ceases to exist and is then updated & recreated in that moment. Maybe Planck lengths are the pages of God. Allahu alem.

I guessed average speed but how far or fast is traveled at relativistic speeds relative to each observer 😮

True

the formula is average speed = distance / time

I was the 1000th thumbs up! 😄👍

great video and shirt.

Sir !! Do you still teach in Khan academy!?

Ture ingrained wrong things create a mess in higher classes

It represents the average speed.

What is instantaneous speed then ?

@stewiesaidthat

4 ай бұрын

The speed of causality.

average speed = distance / time instant speed = ? It has the same units but what is on the right side of the equation?

@perkinscurry8665

8 ай бұрын

the same: distance/time except that the distance is how far you travel in 0 seconds ... actually the limit as t approaches zero

@MarkMarconi

8 ай бұрын

​@@perkinscurry8665so its infinity? i found His explanation lagging because isnt It obvious Speed has to be constant ober that time to directly get distance with product , also if speed Changes you can integrate over time to get distance, seems straight Forward to me

@joe_ninety_one5076

6 ай бұрын

dx/dt in one dimension (x).

Not sure it was your best video so far but as always it is sooo great to see your passion for physics and teaching!

Sir's feature ' Sarcasm '

The speed of light isn’t constant because time and distance aren’t constant. It’s not complicated. There is so much wrong in cosmology. It’s almost entirely based on assumptions, assumptions of dark matter assumptions of dark energy assumptions of a universe expanding from nothing into oblivion for no reason assumptions of a single age of the universe and the assumption that everything just appeared from nothing like magic. Redshift is from a light source from a greater mass. Distant galaxies are more redshifted because of the greater amount of mass that the light has to pass by. The vacuum energy is from black holes absorbing space time, not from imaginary inflatons. Dark energy is assumed because the correct differing measures of distance and time are not being taken into account. Matter and energy cannot make or direct themselves and they are only going from order to disorder disproving the idea that they made and directed themselves. The problem is that cosmologists are not considering the actual evidence in front of them. The evidence is one giant elephant 🐘 in the room that the (secular) scientists try their hardest to ignore and pretend that the elephant 🐘 isn’t there when the elephant 🐘 of actual physics is there. The speed of light is NOT constant because the measurements of time and distance are NOT constant throughout the universe. The light from distant galaxies only slows down when it encounters the mass inside of a galaxy according to general relativity which is an observed fact. There’s no excuse for scientists to be making up their own version of physics.

I now know, that I don't hate physics :) Its just that I was taught in a wrong way.

I like your t-shirt 🤩

AGREE

no, it represents average speed.

never had any of proposed problems bs?

So, you made a video to tell us that it's average speed? Really now? Is the channel for kids under 12?

In real life, due to friction and bla bla bla...., every thing becomes a non-uniform motion :. The speed is not constant Except the speed of light in a vacuum. :.speed in real life of an object with mass=total distance/total time= average of the speed of an object.

Ok you got me to click

The speed is the distance that would be traveled during a unit of time. Not that has been traveled. Everybody understands this. This is not his best video...

Sir neevu kannadavara

Reason were are dumb, because he have to unlearned everything we learned with the passage of time that's why forgetfulness is important. And our Education system force us to remember and the same system call us dumb by their categorised method. So my dear young student ask questions don't believe everything what the teacher says.

Wait, so what is distance over time actually? First you say average speed is not distance/time then you say instant speed is not distance/time... Now im lost 😂

@doim1676

5 ай бұрын

@@Luke-lu3pw thx xD

zhi

This take is pretty awful. The way you frame the question the first time, if after instantaneous speed is missing information. The fact you specify a time period of 5 hours gives the implication you are asking for average speed. Speed is still distance over time, to say it's not is just wrong. Instantaneous speed is still what distance over time you will do if you were to keep your speed constant. You really are just playing the pedantic word game here by not giving enough clarity about what you are asking for.

Nonsense

This is nonsense, he came up with the problem himself. Speed is the current state of the car, the ratio of distance to time. Everything else is poetry and has nothing to do with science.

Let's go back to the stone age, what say Mahesh?

@gabarsingh8519

Жыл бұрын

😂😂😂😂

First time i felt your video not much useful.