Speed is NOT distance/time ❌

Speed is NOT distance divided by time.
Please STOP dumbing it down!

There are three problems of doing that.

[1] You lose opportunity to discuss what distance over time REALLY is.
Science is about thinking and this is a great thinking exercise for kids.

[2] You lose the opportunity to discuss actual application of distance/time.
distance/time has an incredible application in life. Your google maps work on the same idea.

[3] You create misconceptions about how to find speed.
Distance/time doesn't give you the speed you see in the speedometers.

So, here's what I think we should do.
Curious to hear your thoughts.

================================================
Follow me at
================================================
Support me and learn more physics at the same time by enrolling in my Udemy course
================================================

[GodSahil]

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

[krwada]

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

[Familyproud-eh]

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 👍🏻

[k.nishanthkamath]

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

[macfrankist]

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.

[kecskemetib]

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! :)

[paulg]

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

[GodSahil]

yeh! something related to class 11th finally!

[adobocado]

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! 🙏

[haroldnowak]

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.

[rafoh]

The other assumption is that this is a straight-line path and not curved.

[SyDatNguyen-rj]

That equation assume you go at a constant speed. Speed varies because you need to speed up, slow down, …

[getnmyoven]

Average speed = distance/time

Fixed it

[neelanjanbanerjee]

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

[vikasj]

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

[biopsiesbeanieboos]

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).

[sveialertlanah]

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

[supercommie]

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

[antrikshfulwani]

I'm wearing the same T-shirt as you right now, and that makes me very happy for some reason.

[fubaralakbar]

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