@9:57, velocity is equal to *displacement* over time, not distance over time. This is a very small but important distinction just as a reminder to those watching! Distance traveled over time is related to speed, which is a scalar quantity. Displacement over time is related to velocity, which is a vector quantity.
How are you going to give a exam the next day after newly learning just the basic formulae for waves that you could read in a book? What grade are you in btw.
14 years old up in Singapore, if your'e in a private school like mine (School of Science and Technology, Singapore). Most likely the mainstreaming academic schools learn this at the age of 15. May I remind you that Singaporeans only start learning physics at the age of 13. If your'e wondering what I learn for science before the age of 13, its just simple science foundations to help us cope in secondary school.
I ALSO DIDN'T UNDERSTAND ANYTHING ABOUT WAVES UNTIL I WATCH PREVIOUS AND THIS VIDEOS .THANKS A LOT.....REALLY IT'S VERY HELPFUL.ONCE AGAIN THANK YOU VERY MUCH ..
Sal, Show what happens when the differential impluse (-+) wave reaches the end of the string, different reflection result, if the end of the string is floating (open) or locked down (shorted) . Keep posting, I'm enjoying.
I had the good fortune to have Richard Feynman as a teacher at Cal Poly. I also was taught by Sir Ronald Syme at Christchurch. The sheer presence of such scholars could never be equaled by a You Tube video. The atmosphere of deep respect for learning and the intellect can’t be matched by a video, nor can the camaraderie and sense of shared purpose. Finally I met my wife in graduate school.She was a distinguished scholar in the Classics dept. whose nickname (unknown to her) was the goddess. The You Tube community hath not her like!
Even though i didn't get any sleep last night, and don't plan to tonight, and even though im stressed like crazy about my AS Physics exam in two days, i still chuckled at 2:20 ^^
i am just wondering, could you please elaborate on how a wave can move in a vacuum without a medium? Sal does a fantastic job thoroughly covering the material, but his true forte is explaining abstract concepts.
you should watch his first video in the introduction to waves he talks about transverse/longitudinal (this comment was from 3 years ago but this might help others)
Can you please do a video on phase change on reflection for light (Where there is a phase change of π on reflection at an interface where there is an increase in optical density, e.g. a higher refractive index such as light going from air to glass. There is no phase change on reflection where there is a decrease in optical density, e.g. a lower refractive index such as light going from glass to air) And explain why that is? Thank you:)
HOLY SHIT THANKYOU SOOO MUCH!!!, I'm kinda abit behind in my physics class and I need some help figuring out what lambda, velocity, frequency is and stuff thanks alot>
THANK YOU SO MUCH!! I have a science project on this and just couldnt understand frequency. This video got me to understand it!! I was so frustrated and freaking out cos i didnt understand! Now I am so much more relaxed!!
Im in an advanced science class and my teacher told us that we have a test on this after 2 classes of him just giving us chapters to read from the textbook XD. Thanks for helping me understand and i will pass this on to my friends who are also having trouble ( the rest of my class ahah)
Because you deal with VELOCITY is this videos examples, should the equations not be solving for DISPLACEMENT rather than DISTANCE? And by the same token, include the DIRECTION of EAST in these cases please? Thanks.
Displacement and distance...transverse waves, like light, travel in straight lines. And this video covers the basics. So no reflection. Just a straight line. And the velocity in reality is speed here but...people into physics tend to use velocity all the time.
Question: If the horizontal axis is time, the period is the "distance" between two peaks, and wavelength is also the distance between two peaks, wouldn't period = wavelength?
Ok I get it now. A wave can't be graphed with a 2D curve, it's a 3D surface _y(x,t) = Asin(ax + bt)_, and period is the distance between two peaks with fixed x and wavelength is the distance between two peaks with fixed t. At any fixed point on the wave with distance _x_ from the origin, the distance between two peaks on the t-y plane is the *period*. At any fixed time t, the distance between two peaks on the x-y plane is the *wavelength*. The two peaks are different.
@9:57, velocity is equal to *displacement* over time, not distance over time. This is a very small but important distinction just as a reminder to those watching! Distance traveled over time is related to speed, which is a scalar quantity. Displacement over time is related to velocity, which is a vector quantity.
Thanks
I love how he repeats stuff as he writes it. I dont know why but it helps for some reason.
Also nice for visually challenged people (just in case) or if anyone is watching in low quality in poor data connection.
Thank u wish I had u as my science teacher!!
Are u still using this account?
Heard ''jerking up and down '' automatically came to check comments
same hahahaa
dammit, same here man! :D
lmao same
Same here lol
This helped me for trigonometric graphs.
couldnt thank you enough!
I wonder how many times Sal has said "Magenta" over the years
A lot
i have finals tomorrow an i didnt understand this until i watched your video thanks
How are you going to give a exam the next day after newly learning just the basic formulae for waves that you could read in a book?
What grade are you in btw.
An*
oh. well glad to see you want to learn. work hard!
dude i learnt a whole chapter hours before the midterm and i got 24/25 even though the test was extremely hard
Sal, I think you're reading my mind! It is just the lesson I wanted you to upload!
Oddly, we just reached this lesson in my physics class. Amazing timing.
digital learning days gang😗✌🏼
Hi
Love your videos, I owe you my degree :P
your videos motivate me to study! thanks :D
that's so true! i want to study hahaha
14 years old up in Singapore, if your'e in a private school like mine (School of Science and Technology, Singapore). Most likely the mainstreaming academic schools learn this at the age of 15.
May I remind you that Singaporeans only start learning physics at the age of 13.
If your'e wondering what I learn for science before the age of 13, its just simple science foundations to help us cope in secondary school.
Sal is a truly talented instructor. I've learned so much from him!
love u Sal! tmrw is my physics test and now for the very first time i am over confident lol .
Dude, you are awesome! You explain things so logically and break subjects down in a way I can understand. Thanks!
Always watch videos from this channel.......
this is saving my life for my physics quiz on thursday; everybody should donate to this channel
peak = crest, i guess.
yep could be either one that your accustomed to
Yes
Yeah
Yess
"Maybe i'm doing it every two seconds"
💀👍
I ALSO DIDN'T UNDERSTAND ANYTHING ABOUT WAVES UNTIL I WATCH PREVIOUS AND THIS VIDEOS .THANKS A LOT.....REALLY IT'S VERY HELPFUL.ONCE AGAIN THANK YOU VERY MUCH ..
These videos helps a lot. Thanks!!
Lol I liked how you counted so fast to 20
In 12:18
Guy Shapira hifi
it was hilarious
Sal,
Show what happens when the differential impluse (-+) wave reaches the end of the string, different reflection result, if the end of the string is floating (open) or locked down (shorted) .
Keep posting, I'm enjoying.
These videos honestly make me wonder why I need school I could literally just learn everything from TH-cam
I had the good fortune to have Richard Feynman as a teacher at Cal Poly. I also was taught by Sir Ronald Syme at Christchurch. The sheer presence of such scholars could never be equaled by a You Tube video. The atmosphere of deep respect for learning and the intellect can’t be matched by a video, nor can the camaraderie and sense of shared purpose. Finally I met my wife in graduate school.She was a distinguished scholar in the Classics dept. whose nickname (unknown to her) was the goddess. The You Tube community hath not her like!
@@AmasaTony81947 you are really ignorant to assume that every lecturer is as passionate as Richard Feynman and that everyone is as fortunate you are.
May you live long Sal ... I could not clear this concept thought out my life.
Even though i didn't get any sleep last night, and don't plan to tonight, and even though im stressed like crazy about my AS Physics exam in two days, i still chuckled at 2:20 ^^
His videos are absolute gold
He clarifies everything
80% of the people watching have either an exam or test in the next few days
Qaz if you have an exam or test use the notes you got from school your teachers gave you ways to study and also helped you comprehend in class
Tomorrow
well.. not me
Me 1 hour and 15 mins
Well you're not wrong. I've got a test tomorrow. :)
i am just wondering, could you please elaborate on how a wave can move in a vacuum without a medium?
Sal does a fantastic job thoroughly covering the material, but his true forte is explaining abstract concepts.
PartVIII it can't lol
Counting to 20 with Sal.
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,19,20.
isnt the peak called a crest ?
+Ehtisham Khan Same thing, different ways of saying it.
Ehtisham Khan American vs British
finally after 6 years i know what is that mean ,, the first thing i will do when i get my first paid i will denote to this academy
OMG, I understood this in class, but Khan Academy never fails to blow my mind even when I think I understand something.
All waves are created by Sal and his string because he is god, Thankyou so much SalJesus
My physics teacher calls a periodic wave a transversal wave
+Thomas McDonnell Mine too, I'd assume it's interchangeable.
you should watch his first video in the introduction to waves he talks about transverse/longitudinal (this comment was from 3 years ago but this might help others)
will be having the biggest physics examination in my high school this Tuesday and this video helps me a LOT. thankyouu!
Holy crap! I actually understood everything that you said! And the good thing is you didn't bore me to death... A+
Khan, your vids are great.. they've helped me a ton. But why do you not win some sort of award?!
20 people are not meant for STEM.
great video sal, soooo helpful, hopefully itll be enought for my exam
Can you please do a video on phase change on reflection for light (Where there is a phase change of π on reflection at an interface where there is an increase in optical density, e.g. a higher refractive index such as light going from air to glass. There is no phase change on reflection where there is a decrease in optical density, e.g. a lower refractive index such as light going from glass to air) And explain why that is? Thank you:)
HOLY SHIT THANKYOU SOOO MUCH!!!, I'm kinda abit behind in my physics class and I need some help figuring out what lambda, velocity, frequency is and stuff thanks alot>
wow, this is one your best videos ever! thank you for such a clear explanation.
this is actually the most helpful thing of my life thank you so much sal
The highest point is actually called a crest
Ya, I also got confused there
they are both the same thing, crest and peak
im following every video on waves and optics :)
pleasee keep goin
That was an awesome video. I have never understood frequency and hear it so often. The wave application is really cool.
You should actually do a video on standing waves, nodes, frequencies (or just pull out the topics from AP Physics B)
Thanks now I'm ready for my test. Good job clearing it out for me.
THANK YOU SO MUCH!! I have a science project on this and just couldnt understand frequency. This video got me to understand it!! I was so frustrated and freaking out cos i didnt understand! Now I am so much more relaxed!!
So helpful, for some reason I never learned this s#*% in high school, now I'm caught up.
Thanks man got a physics test tomorrow, saved me.
Literally , From my Bottom of Heart ❤️ Thank You Master Teacher ! This is one the Bestest Explaination I've got since 2 yrs !
this video is very helpful..thanks man
Im in an advanced science class and my teacher told us that we have a test on this after 2 classes of him just giving us chapters to read from the textbook XD. Thanks for helping me understand and i will pass this on to my friends who are also having trouble ( the rest of my class ahah)
Sal, can we please get some Light waves and interference videos? Its really needed.
Because you deal with VELOCITY is this videos examples, should the equations not be solving for DISPLACEMENT rather than DISTANCE? And by the same token, include the DIRECTION of EAST in these cases please? Thanks.
Displacement and distance...transverse waves, like light, travel in straight lines. And this video covers the basics. So no reflection. Just a straight line. And the velocity in reality is speed here but...people into physics tend to use velocity all the time.
***** Thanks very much. I will be coming back to these videos in the early new year . . .
Khan academy is the saviour❤
The only reason is to get a college certificate for evidence SUPER non-sensical...........I'm learning more from him than all my teachers combined.
Thanks, Now I can do my work.
thanks mate. heaps of help
excellent, thanks from a Dad!
great video... excellent way of explaining
Really good video. Thanx it helps alot
could you please do more videos on electrostatics. more examples etc. and also trigonometry, the identities,radians etc
this was really helpful thank you
Thank you so much! Great Video!
thank you very much, it is really really help
Thanks Khan you made my life so much easier :)
You should build your own school :-)
wow very good way to explain.
'hopefully i found that helpful' did you say??
DAMN RIGHT i did, thats equivalent to 3 2hrs physics lessons!!
So so so much helpful
Please continue making videos
We are with u
U re doing an awesome job
Really perfection 💘
yo what program do you use to draw out the lectures ? also, thanks for the help.
omg you are so much better than my my teacher
thankyou, have a science exam next week
Thanks a nice brush up for my basics =)
I wish I could like this video more than once.
awesome tutorials!!..clear explanation!! :)
thank you that is absolutely logical
Also, just a note, amplitude mathematically is (max-min) x 0.5
thanks
Corona Virus online school gang.
v good ......thankyou
I really love your videos, thank you
Sal attempts to count to 20 in one second
watching the colorful lines in hd like a boss
Thanks so much, dude!
Thank you!!!
thank you. thank you. thank you.
thats where the peak to trough expression comes from in investing.. interesting.
Thankful
thank you sal
Thanks!! -Norway-
(y) awesome..................video.......!!!!!!! thanks :) a lot......
Nice good information
i love you sal!
Question: If the horizontal axis is time, the period is the "distance" between two peaks, and wavelength is also the distance between two peaks, wouldn't period = wavelength?
Ok I get it now. A wave can't be graphed with a 2D curve, it's a 3D surface _y(x,t) = Asin(ax + bt)_, and period is the distance between two peaks with fixed x and wavelength is the distance between two peaks with fixed t.
At any fixed point on the wave with distance _x_ from the origin, the distance between two peaks on the t-y plane is the *period*.
At any fixed time t, the distance between two peaks on the x-y plane is the *wavelength*.
The two peaks are different.
putting this on x2 speed makes this guy sound like a mad scientist