We made quiz questions to help you review the content in this episode! Find them on the free Crash Course App! Download it here for Apple Devices: apple.co/3d4eyZo Download it here for Android Devices: bit.ly/3TW06aP
Sound is a form of energy that produces sensation of hearing in our ears. Sound is produced when a body vibrates. Sound needs a medium to travel. It cannot travel in vacuum. Sound travels faster in solid medium (like wood) as compared to water and air. All musical instruments have vibrating parts/which produce sound. In human beings, sound is produced by the voice box or the larynx. We hear through the vibration of our eardrum, whenever sound reaches our ears. The number of oscillations per second is called the frequency of oscillation (f) and is expressed in hertz (Hz). A frquency of 1 Hz is one oscillation per second. The time needed to complete one oscillation is called time period (T). Hence, the number of oscillations per unit time is the frequency of wave f = 1 /T. The maximum displacement of the wave crest from the central position on either side is called its amplitude. We differentiate sounds on the basis of their amplitudes and frequencies. A human being can hear sound waves within a range of 20 Hz to 20,000 Hz. Some animals like dogs can hear sounds higher than 20,000 Hz. The larger the amplitude of vibration, the louder is the sound. Loudness of sound is proportional to the square of the amplitude of the vibration producing the sound. The loudness is expressed in a unit called decibel (dB). Shrillness or the pitch of a sound depends upon its frequency. Higher the frequency, higher is the pitch and vice-versa. Unwanted, unpleasant sound is noise. Loud noise produces noise pollution, which is harmful and may cause hearing impairment. The velocity of sound in air is approx.330ms−1 under standard temperature and pressure conditions. It varies with temperature, pressure, humidity and density of medium.
My friends and I were walking through a high end bank looking for a bathroom when we were all in high school and when we reached the third floor, it sounded like a fire alarm was going off. We were looking around and none of the employees or customers were reacting in the slightest, and just kept going on with business. Thinking something was wrong, we left. Looking back, all of the employees and customers were 45-60 years old. After watching this video, I realize it was probably one of those security systems you were talking about, because the sound wasn't particularly urgent, but it was really high pitched. More than anything else, I'm kinda pissed that it worked. They got us to leave, bladders full, under the cloak of confusion at the sound. I feel so played.
One thing I missed in this episode is that even though we cannot hear sounds outside of our hearing spectrum, it doesn´t mean that they have no effect on us.
It's frequency is way too much so therefore the eardrums can't produce much amplitude in order for us to hear because the eardrum don't have enough time to go back and forth much distance look it's complicated just Google it
5:06 gosh, I served in US air base where air planes and fighter jets frequently take off and land. That really did drive me round the bend. Miraculously, I managed to retain my hearing. Cheers for the instructive lecture and reminding me of that memory mate!
I'm teaching an introductory music technology course at university this fall. This is my saving grace for not having to dive into the physics!! This came out at the perfect moment in time.
I love crash course but I wish you'd guys would sloooow down a little itty bit, sometimes you guys (and gals) spew out information so fast it takes two times through for me to really soak it all in. I love this course though, thank you guys!
It's useful to describe sound waves as pressure waves, because we can build devices that detect those changes in pressure. I love CrashCourse Subscribed!
human beings are amazing. i started looking up physics stuff because of a psychedelic experience in which i learned how particles and waves work, and now i see that everything i saw was just science. interesting stuff
Ah this was so good! I need to know the physics of something before I can understand it, so this helped my sound production studies so much. Thank you!
12Rman21 lol. so serious.. can't understand it was a joke? i wouldn't have watched this video if i wasn't interested in science. go go.. go troll somewhere else. you seem to be better than me. no need to look down at people. now arrogance.. that's the worst. blocked. no need to reply.. i know you have something witty back to say..
It's really quite fascinating to realize that the correlation between music & mathematics is literally off the charts. I didn't learn how to read music (other than strumming chords on a guitar) until I was almost 50... Or so I thought!! I really did try my best... well, actually what I thought was my best, to learn how to play musical notes on the guitar when I was in middle school as well. Honestly, I don't know if this is true for everyone but I was super surprised at what it took for me to understand fairly basic all-around music theory. What it took for things to click for me was to 1st apply it on a piano rather than a guitar. And to go even one stepfurther, if someone would have told me right off the bat how music theory is so dependant mathematics to the point of being inseperable, I would have looked at it from a completely different perspective. BUT in as much as I know this to be soooo completely true/irrefreputable, it's still really hard to wrap my head around the very idea that such a creative artform such as music depends so heavily on something as technical as mathematics. I guess that subconsciouly, I always felt like I had to hide one side of my brain or the other because having two dominant sides ofthe brain is an oxymoron 🤷 ✌️💞✌️
I'm going to start my sound engineering degree next month such an interesting topic.. as a musician it fascinates me, I think i'll be having fun. thank you for this video very well explained thank you =)
As far as sound this takes effect. Light can measure distance in the universe. There is a difference. Sound can travel very far but can be blocked at anytime therefore cannot be used as measure instrument. But this great vid and great information.
That ambulance was moving down the street at nearly Mach 1, passing someone at that speed would produce a more interesting effect than a pitch change. Just kidding, great series, good visualization.
@6:50 the number of which you need to take the log is not "a trillion Watt per metre-square". it has no dimension since you divided a quantity by another quantity of the same dimension or unit. So it's just "a trillion", period. This why (deci)bels are so confusing: to compute them, you need to take some reference point (noted I_0 in the video); this is why there are actually several (and possibly, infinitely many) decibel scales depending on the reference chosen for a particular application. Oh, and there actually is an absolute maximum to that scale: when the sound wave becomes so intense that the depressed phase of the wave basically becomes a vacuum or "cavitates".
Descpribing sound as pressure waves makes sense why a jet flying in supersonic speeds near buildings will do some serious damage. Since it creates a difference in pressure in the air.
Wait, measure the distance of stars? I would say the relative speed the star is moving to earth. Also I highly recommend that everybody build at least one set of hifi speakers, measuring the impedance and characteristics, running simulations, applying Thiele/Small theory in the design of passive crossovers. I learned a lot by doing that three years ago just for fun. Buying a calibrated microphone is not that expensive and a nice DIY project can be made, learning A LOT about sound. Hmm. Now that I think of it, I forgot most of it. :-)
Now, I think I have a good idea. Since energy is Force times the distance the force is applied. Think of a pulse. You oscilate once which means you apply a force up and down on a rope. The part of the rope you pulled up and then pulled down. You only pulled down on that part of the rope. That part of the rope pulls down on the next part of the rope just as the part you pulled down goes down. And then it continually is replaced. (i.e think of a wave at a stadium. The people to your left moving up pulled you up and then as they went down their movement pulled you down as well as you pull down the people to your right.)
In Science we were learning about Sound vs Light. I may know what's the difference to them or what's similar to them. I'll tell ya something. What I know is sound can go through any sort of objects that are opaque. Light shines through any object that are transparent or translucent. Ive learned it since in high school and even I'm in Year 7
Hey Crash Course, I really like this channel. The diversity of topics and depth of insight is something that is, in my opinion, unrivaled by most other RUclips channels. The idea of this channel alone, that being videos of moderate length explaining a range of topics in detail, is priceless. Now more than ever it is vitally important to the American economy that our citizens be intellectually literate, especially in fields such as science and technology. Come to think of it, it may be a good idea for you guys to make a STEM (Science, Technology, Engineering, and Mathematics) playlist. Just a thought. On another note, what would you guys/girls (meaning whoever is reading this) of an interview series on Crash Course? It would be really interesting to see Crash Course collaborate with scientists, artists, authors, poets... etc. Couple that with longer interviews with the guest and I think it would have the potential to really grow the channel and even further diversify the content, appealing to a different breed of knowledge junkie. I can only hope that some high profile names in the various fields of expertise would be willing to collaborate. Richard Dawkins for biology, Lawrence Krauss for particle physics, Bill Nye for climate change and engineering, Cornell West for social and political reformation and history, and so on and so forth. I believe that and do of those names have collaborated with the channel Big Think (which is another channel that I love), and they have only have about 1/3rd of the amount of subscribers that Crash Course has. Not to mention their connection to PBS, which may hold some sway. I believe that Crash Course is connected to a few other large channels as well, like SciShow, which could also host those sort of interviews and collaborations.
Objection! The apparent frequency is changing as the source moves. Meaning the perception that the pitch is changing is false, its the amplitude that is changing
This is just what I nees to speed up my understanding before getting into the math used to describe the physics, btw nice Feynman books I have the spanish-english version, really nice book (I'm a native spanish speaker)
Why sound waves traveling in all directions ?? Recently I've read about sound wave propagation. Let's look on loudspeaker. If it creates sound waves by pushing and pulling the air in front of it , how we can hear sound when we are behind the loudspeaker or above or under?
Dear, Crash Course, I am wondering what is the name of the song they used for the H3 Ethan reference. I want to get that sound file for my mp3 player. It sounds nice even in this episode. Keep up the wonderful work crash course.
"Light" is the episode 24 of Crash Course Astronomy and not Crash Course Physics........ so basically, you don't need to wait cause it's already there....go to the previous episodes of Crash Course Astronomy.. :)
The spring constant depends on what the spring is made from. It's a measure of "stretchiness", it's not related to length (until you stretch it so far that it won't go back).
Waves transmit energy and not matter. My question was what causes this? to solve the problem of waht is a wave anyways? Do we call it energy? If so what qualities of energy can be revealed in a wave that also translates into how to measure it. How to understand it.
Sound travels faster and farther in denser mediums like steel. Yet it is stopped by heavier materials which is just another way to say by denser materials and this suggests that steal must be good at stopping it. Isn't there a contradiction here? I am confused.
WOW you are just excellent, why might the note c6 have a dark colour istead of bright? Ihave downloaded a pitch app and used my voice to draw this conclusion.
Pokemon Go!!! Walk on the street and sticking your eyes on the Phone playing Pokemon Go and there you go, "Crash" course XD. And Ash Ketchum's cap in the Doppler effect too XD
![Coheed and Cambria - Searching for Tomorrow [Official Video]](http://i.ytimg.com/vi/hDsYGLbmadg/mqdefault.jpg)
We made quiz questions to help you review the content in this episode! Find them on the free Crash Course App!
Download it here for Apple Devices: apple.co/3d4eyZo
Download it here for Android Devices: bit.ly/3TW06aP
Dr. Somara has some of the most intense eyes I've seen yet. I feel like she could stare down a goldfish and win.
Sound is a form of energy that produces sensation of hearing in our ears.
Sound is produced when a body vibrates.
Sound needs a medium to travel. It cannot travel in vacuum.
Sound travels faster in solid medium (like wood) as compared to water and air.
All musical instruments have vibrating parts/which produce sound.
In human beings, sound is produced by the voice box or the larynx.
We hear through the vibration of our eardrum, whenever sound reaches our ears.
The number of oscillations per second is called the frequency of oscillation (f) and is expressed in hertz (Hz). A frquency of 1 Hz is one oscillation per second.
The time needed to complete one oscillation is called time period (T). Hence, the number of oscillations per unit time is the frequency of wave f = 1 /T.
The maximum displacement of the wave crest from the central position on either side is called its amplitude.
We differentiate sounds on the basis of their amplitudes and frequencies.
A human being can hear sound waves within a range of 20 Hz to 20,000 Hz. Some animals like dogs can hear sounds higher than 20,000 Hz.
The larger the amplitude of vibration, the louder is the sound.
Loudness of sound is proportional to the square of the amplitude of the vibration producing the sound. The loudness is expressed in a unit called decibel (dB).
Shrillness or the pitch of a sound depends upon its frequency. Higher the frequency, higher is the pitch and vice-versa.
Unwanted, unpleasant sound is noise. Loud noise produces noise pollution, which is harmful and may cause hearing impairment.
The velocity of sound in air is approx.330ms−1
under standard temperature and pressure conditions. It varies with temperature, pressure, humidity and density of medium.
Huda Mohyadeen thanks
@@haleydavidson7693 why u say that
Tryann Tomlinson she gave me some extra notes to write down
Thanks thanks friend,I got a bad memory so this is good to look back at
omg i should've gone to the comment section sooner... just spent so long on learning these exact same points😂
*Thank you so much*
My friends and I were walking through a high end bank looking for a bathroom when we were all in high school and when we reached the third floor, it sounded like a fire alarm was going off. We were looking around and none of the employees or customers were reacting in the slightest, and just kept going on with business. Thinking something was wrong, we left. Looking back, all of the employees and customers were 45-60 years old. After watching this video, I realize it was probably one of those security systems you were talking about, because the sound wasn't particularly urgent, but it was really high pitched. More than anything else, I'm kinda pissed that it worked. They got us to leave, bladders full, under the cloak of confusion at the sound. I feel so played.
and free energy?PLEASE!!!!!!!!!!!!!!!!!!!!!!!
Crazy
Good thing I was never able to hear frequencies above 5000 Hz.
(515)
@@noname-ue7lb ur a weird guy. Are u the joker?
at 6:39 is where I have to see myself out of the door thank you
One thing I missed in this episode is that even though we cannot hear sounds outside of our hearing spectrum, it doesn´t mean that they have no effect on us.
+
It's frequency is way too much so therefore the eardrums can't produce much amplitude in order for us to hear because the eardrum don't have enough time to go back and forth much distance look it's complicated just Google it
This is such a sound video
I hate hearing those types of puns. Get out orals I'll turn off the internet.
With these qualities, no wonder Crash Course Physics is such a resounding success.
+
+Chow Tom 😂😂😂 Well done mate
You deserve a like
5:06 gosh, I served in US air base where air planes and fighter jets frequently take off and land. That really did drive me round the bend. Miraculously, I managed to retain my hearing. Cheers for the instructive lecture and reminding me of that memory mate!
I'm teaching an introductory music technology course at university this fall. This is my saving grace for not having to dive into the physics!! This came out at the perfect moment in time.
I love crash course but I wish you'd guys would sloooow down a little itty bit, sometimes you guys (and gals) spew out information so fast it takes two times through for me to really soak it all in. I love this course though, thank you guys!
4:05 did anyone realise the dogs brown patch shifts from right to left on his face
?
Thank you for providing the information! Even if this video is 6 years old it still helps a lot! Thanks.
first timer here.
Your class is amazing!
Thanks for being so clear.
When she was on the doppler effect part an ambulance went by my open window. lol perfect timing.
the whole of my words can t even express how much i love this channel and how it helps me
Her voice is angelic.
It's useful to describe sound waves as pressure waves, because we can build devices that detect those changes in pressure.
I love CrashCourse
Subscribed!
human beings are amazing. i started looking up physics stuff because of a psychedelic experience in which i learned how particles and waves work, and now i see that everything i saw was just science. interesting stuff
Now I know more about sound energy and what it dose thank you I am your #1 fan
someone get this channel nominated for nobel prize awards
like tbh this is the best of all the crash courses she is an amazing teacher and even the graphics and intro are 1000 times better
Ah this was so good! I need to know the physics of something before I can understand it, so this helped my sound production studies so much. Thank you!
This is the dopest educational show in the history of the world
XD true
False
That one robot show is better
have a hard time sleeping? put the decibel equation part on loop. it'll put u right out
Lol!
oh that was mean... but stil...lol
Pssh, speak for yourself. I make a career in this stuff.
12Rman21 lol. so serious.. can't understand it was a joke? i wouldn't have watched this video if i wasn't interested in science. go go.. go troll somewhere else. you seem to be better than me. no need to look down at people. now arrogance.. that's the worst. blocked. no need to reply.. i know you have something witty back to say..
+Sham Neo k
It's really quite fascinating to realize that the correlation between music & mathematics is literally off the charts.
I didn't learn how to read music (other than strumming chords on a guitar) until I was almost 50... Or so I thought!!
I really did try my best... well, actually what I thought was my best, to learn how to play musical notes on the guitar when I was in middle school as well.
Honestly, I don't know if this is true for everyone but I was super surprised at what it took for me to understand fairly basic all-around music theory. What it took for things to click for me was to 1st apply it on a piano rather than a guitar.
And to go even one stepfurther, if someone would have told me right off the bat how music theory is so dependant mathematics to the point of being inseperable, I would have looked at it from a completely different perspective.
BUT in as much as I know this to be soooo completely true/irrefreputable, it's still really hard to wrap my head around the very idea that such a creative artform such as music depends so heavily on something as technical as mathematics.
I guess that subconsciouly, I always felt like I had to hide one side of my brain or the other because having two dominant sides ofthe brain is an oxymoron 🤷 ✌️💞✌️
Thank you so much! These videos are even better when I'm just curious about certain things
I like the human being hosting this. She is good human.
I love how passionate she is! Love the videos 👍🏼
"It happens with light, too... but more on that much later"
Aw man, but relativistic mechanics are my favorite! :(
Me wants some Lorentz contraction!
I'm going to start my sound engineering degree next month such an interesting topic.. as a musician it fascinates me, I think i'll be having fun. thank you for this video very well explained thank you =)
4:50 I see you put h3h3 in there...
It’s actually Sea get your punctuation write and it’s also they’re idoit dum arce
woah bro calm down just becuz he maed a hORIBAL spelign acksidint duzent meen u gotta be so meen 2 him
The best sounding video ever
this channel is the best on youtube.....
Finally after several useless high view videos, I clearly understood the definition of decibel! Thanks a lot for great explanation
As far as sound this takes effect. Light can measure distance in the universe. There is a difference. Sound can travel very far but can be blocked at anytime therefore cannot be used as measure instrument. But this great vid and great information.
Eardrum in our ear is also called tympanum
Excellent video 😃 hopefully I can pass this final tomorrow
That ambulance was moving down the street at nearly Mach 1, passing someone at that speed would produce a more interesting effect than a pitch change. Just kidding, great series, good visualization.
This is a good video to teach deaf people how sound works, even if they can't hear them. Thanks!
I love your videos, but why don't you make them a third longer while reducing your talking speed by one third?
This is a hilariously great idea. +++++++++
You could mess with the speed if it's too quick for you. Time is bandwidth.
It's also money for them, so..
Apatheism but it also warps the sound "chump"
I slowed it down but it was STILL too fast
@6:50 the number of which you need to take the log is not "a trillion Watt per metre-square". it has no dimension since you divided a quantity by another quantity of the same dimension or unit. So it's just "a trillion", period. This why (deci)bels are so confusing: to compute them, you need to take some reference point (noted I_0 in the video); this is why there are actually several (and possibly, infinitely many) decibel scales depending on the reference chosen for a particular application. Oh, and there actually is an absolute maximum to that scale: when the sound wave becomes so intense that the depressed phase of the wave basically becomes a vacuum or "cavitates".
I wish there was a crash course music! But, this is definitely a start 😊
Did I just see when Ethan from H3H3 during to rock scene?!
Glad I'm not the only who noticed. I never thought I'd see Ethan In a Crash Course video. It's like two worlds that could never really mix.
+Dooality I know right I thought I was seeing things.
I never would have thought I'd seen Ethan in his Pikachu outfit on Crash Course.
Descpribing sound as pressure waves makes sense why a jet flying in supersonic speeds near buildings will do some serious damage. Since it creates a difference in pressure in the air.
My eyes glaze over when the math starts LOL
Wait, measure the distance of stars? I would say the relative speed the star is moving to earth. Also I highly recommend that everybody build at least one set of hifi speakers, measuring the impedance and characteristics, running simulations, applying Thiele/Small theory in the design of passive crossovers. I learned a lot by doing that three years ago just for fun. Buying a calibrated microphone is not that expensive and a nice DIY project can be made, learning A LOT about sound. Hmm. Now that I think of it, I forgot most of it. :-)
thank god for this channel
Sounds great😂thank you for the lesson
lmao I can't believe you put an h3h3 reference in here...
can u link the time plz
4:45 lol
That was mind blowing
Also note that the low end of safe hearing is 1 pikawatt per square meter.
The smartest show I know made a reference to the stupidest show I know
Dear crash course can you guide how these fantastic animations are designed?
Now, I think I have a good idea. Since energy is Force times the distance the force is applied. Think of a pulse. You oscilate once which means you apply a force up and down on a rope. The part of the rope you pulled up and then pulled down. You only pulled down on that part of the rope. That part of the rope pulls down on the next part of the rope just as the part you pulled down goes down. And then it continually is replaced. (i.e think of a wave at a stadium. The people to your left moving up pulled you up and then as they went down their movement pulled you down as well as you pull down the people to your right.)
Wooow such a great video, I love this chanel!
That Pikachu while describing about picowatts was amazing.
In Science we were learning about Sound vs Light. I may know what's the difference to them or what's similar to them. I'll tell ya something. What I know is sound can go through any sort of objects that are opaque. Light shines through any object that are transparent or translucent. Ive learned it since in high school and even I'm in Year 7
what is difference between Isolation and Separation in Biophysics??? n pls upload vdo on electrophoresis.
Crash course on music theory please :)
First video ever I had to slow down
crash course music theory for the love of jebus
They could have that Adam Neely guy do them
Hey Crash Course, I really like this channel. The diversity of topics and depth of insight is something that is, in my opinion, unrivaled by most other RUclips channels. The idea of this channel alone, that being videos of moderate length explaining a range of topics in detail, is priceless. Now more than ever it is vitally important to the American economy that our citizens be intellectually literate, especially in fields such as science and technology. Come to think of it, it may be a good idea for you guys to make a STEM (Science, Technology, Engineering, and Mathematics) playlist. Just a thought.
On another note, what would you guys/girls (meaning whoever is reading this) of an interview series on Crash Course? It would be really interesting to see Crash Course collaborate with scientists, artists, authors, poets... etc. Couple that with longer interviews with the guest and I think it would have the potential to really grow the channel and even further diversify the content, appealing to a different breed of knowledge junkie. I can only hope that some high profile names in the various fields of expertise would be willing to collaborate. Richard Dawkins for biology, Lawrence Krauss for particle physics, Bill Nye for climate change and engineering, Cornell West for social and political reformation and history, and so on and so forth. I believe that and do of those names have collaborated with the channel Big Think (which is another channel that I love), and they have only have about 1/3rd of the amount of subscribers that Crash Course has. Not to mention their connection to PBS, which may hold some sway. I believe that Crash Course is connected to a few other large channels as well, like SciShow, which could also host those sort of interviews and collaborations.
Thanks Dr. Somara!
Omg you added Ethan!!!!!
Wow, PoGo Fever has even infected Crash Course!
I know, right?
-Nick J.
CrashCourse CrashCourse responded to my comment! :O
Unrelated: my first comment typed with bépo keyboard layout.
lol
I have no idea what you are torquing about.
King PufflePuff 😆
Objection! The apparent frequency is changing as the source moves. Meaning the perception that the pitch is changing is false, its the amplitude that is changing
4:48 Was this a reference to H3H3s EDM concert video
Yea
Lol it is
That unsolved Rubik’s cube is making me sad I just wanna get in there solve it and tell them to leave it alone
You coulndt even solve it
First video on this channel, and I did not expect at all to see Ethan down here! Really useful video btw papa bless.
This is just what I nees to speed up my understanding before getting into the math used to describe the physics, btw nice Feynman books I have the spanish-english version, really nice book (I'm a native spanish speaker)
Why sound waves traveling in all directions ??
Recently I've read about sound wave propagation. Let's look on loudspeaker. If it creates sound waves by pushing and pulling the air in front of it , how we can hear sound when we are behind the loudspeaker or above or under?
There should be a CrashCourse section on Linguistics :'(
Greetings from Chile, South America.
Incredibly informative! It's okay to be smart. :)
Dear,
Crash Course,
I am wondering what is the name of the song they used for the H3 Ethan reference. I want to get that sound file for my mp3 player. It sounds nice even in this episode. Keep up the wonderful work crash course.
Episode 24 "Light" confirmed.... damn, still have to wait so long...
"Light" is the episode 24 of Crash Course Astronomy and not Crash Course Physics........ so basically, you don't need to wait cause it's already there....go to the previous episodes of Crash Course Astronomy.. :)
"Light" is episode 24 of Crash Course Astronomy'
Oh... seen it already. But here's to hoping there will come a physics episode on light!
Thanks for this channel!
hello, crash course people, please make a video on spring constants and if we change the spring lenght what happens to its constant??
The spring constant depends on what the spring is made from. It's a measure of "stretchiness", it's not related to length (until you stretch it so far that it won't go back).
Great birthday present! :D
It’s been a while since I’ve been following your videos, and I must say, they are amazing! By any chance, is there a scope for business collaboration?
Waves transmit energy and not matter. My question was what causes this? to solve the problem of waht is a wave anyways? Do we call it energy? If so what qualities of energy can be revealed in a wave that also translates into how to measure it. How to understand it.
Waw , this was amazing ✨
This is such a sound video.
do a video on ultrasound! specifically diagnostic medical sonography
*_Awesome crashcourse keep creating such crucial videos_*
watching this to help me do my uni HW haha
She has the best voice ever!
Thank you so much! This is extremely helpful!!!
this video helped me alot
please show us something about free electricity?PLEASE!!!!!!!
Thanks! This is really helpful for my physics revision
Interesting. Simple and compact infos
I love her videos!!
7:21 me when I stub my toe
Man thats sad
Feel bad
What do I do
Talk about standing waves!
Now I actually understood the Intro....It shows up animations, in association with all chapters....
Sound travels faster and farther in denser mediums like steel. Yet it is stopped by heavier materials which is just another way to say by denser materials and this suggests that steal must be good at stopping it. Isn't there a contradiction here? I am confused.
Looking forward to next week :-)
WOW you are just excellent, why might the note c6 have a dark colour istead of bright? Ihave downloaded a pitch app and used my voice to draw this conclusion.
Pokemon Go!!! Walk on the street and sticking your eyes on the Phone playing Pokemon Go and there you go, "Crash" course XD.
And Ash Ketchum's cap in the Doppler effect too XD
great video
What happened to the other guy, I found him to give much more information and it made more sense.
I was studying this today, probably should do it again 😥
This was really fun to learn !