Collisions: Crash Course Physics #10
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- Опубликовано: 2 окт 2024
- COLLISIONS! A big part of physics is understanding collisions and how they're not all the same. Mass, momentum, and many other things dictate how collisions can be unique. In this episode of Crash Course Physics, Shini sits down to lead us through an understanding of collisions. Plus, she brings along our old friend Sir Isaac Newton.
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Produced in collaboration with PBS Digital Studios: / pbsdigitalstudios
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Hey Crash Course
I was wondering if you guys could maybe start a series on music theory. It would be nice to have for musicians wanting to improve their work. It could cover topics such as chord progression, scales, Minor/Major...etc.
If you read this comment please consider, and thanks for taking the time to read it. Keep up the good work.
Totally yes, same here i need music theory too.
Yes pleaseee!! I'm certain many people will benefit from this too!
There's a book called 'The Theory of Sound' by Baron J.W.S. Rayleigh and the first chapter of vol I is all about musical notes and the ratio relations between them. pdf available upon a googling and it's well interesting
YES best idea I’ve ever heard on RUclips
Studying with RUclips is easier than trying to sit through class. If I don't catch something I can always go back and rewatch it and better understand. Whereas in a classroom I'm left numb from not catching everything and hence don't learn a damned thing. Thank you for your videos they are much appreciated.
me: im going to read my barron's book for physics
me instead: watches physics crash course while debating making brownies
update: i made the brownies and will be giving them to my classmates tomorrow
S😝
Yes, yes.. mmhm
I understand...
some of these words
😂
I can pretty much relate...
i relate so much =D
Just watch it like 4 times u’ll get it, dat what I did
Speedy thing goes in, Speedy thing comes out.
👍
👍
You can't explain that!
ooh now I want to play portal 2 all over again. Don't help me procrastinate ;p.
i understand the portal reference, but I don't know why I first read this in cgp grey's voice
Just took my physics final today. these videos were really helpful to review with. 😊
Great!
-Nick J.
*Is just watching due to nerdism*
You might have to wait to see if that statement is true or false.
+Overkillermark2 Bruh!! :)
+MegaFarinato I say they were. I got an 89!!! 😁
Collision Course Physics
How did this not occur to ANYONE else??? Hats off to you.
-Nick J.
I do not understand can you please explain to me
The Commentator f
they should change the playlist name
crash = collision
crash course = collision course
This speaker has like the perfect voice for explaining things on the internet
How do I manage to hate school so much, yet still watch every Crash Course video?
No homework?
+Matthew Kessler but homework is important so we can apply what we learned.
You aren't forced to think too heavily about the topics at times you don't want to.
Because school offers so many boring physics topics and boring ways to learn them.
Try to ask your teachers questions about things you learned here at crash course and which you wanna learn more about.
This was uploaded...
...the day after my physics exam...
F
Copy cat
F
dont copy.
sorry man
She speaks so flawlessly!! And clearly !!! She can simplify even the hardest of the topics !!!
I honestly though she said a bag of bees rolling down a hill that would be easy to stop.
NOTE DO NOT ATTEMPT TO STOP A BAG OF BEES WITH BEAR HANDS.
mozayeniml LEAVES not bees
Bears. eat. beets
"every action has and equal and opposite reaction."
-except when we both start rappin!-
mgk vs eminem
im satisfied with your pun, its non-stop. You have no idea how long i've waited for this.
Isaac Newton v bill nye
I’ve accelerated the mind of mankind
The integral sec y dy from 0 to 1/6 of π is log to base e of √3 times the 64th power of what?
Can't wait until we start discussing electricity and electric circuits! These physics episodes are the highlight of my Fridays :D
Perfectly inelastic?? UGH, ECONOMICS!
Miles Quickster BRUH
how is it that i can have a teacher tell me something for an entire semester but won't understand it until i watch a 10 minute crash course video? i'm killing this physics final today!
Please fix that rubix cube, it's driving me insane.
Esoteric Botanist dunno, but yeah
yeah me to i do not like it
it is meant to be that way
Ocd
o my gosh yess me tooooo
2:20 - 2:31 = U said impulse is the "integral of the net force on an object over time", but then added "in other words- it's change in momentum". I'm confused. I thought force was change momentum (d(mv)/dt). How can impulse, which is the integral of force, also be a measure of change in momentum?
yes queen
She's pretty
+Allen Jasper Her eyes are hypnotic!
Nori Stockholm's syndrome is tragic
1:48
i really expected that cat to yowl and fly away from the bag of leaves
This video helped me understand this concept just in time for the physics subject test this Saturday! All the love, crash course. xoxo
Woohoo!
-Nick J.
Hey +CrashCourse, after this series is done, will you guys make a Crash Course about the Modern Physics (Quantum)? Pretty Please? I hope there's math too...
came fo the knowledge stayed 4 the backgrounds, really love the animation guys , .......gr8 movez...... keep it up.
Indiana Jones died just so we could learn about momentum. We must ace our physics tests to not let his death go in vain
Crash course is the best series ever.
Taking my physics final in like 7 minutes
This is a great video!! Thank you!! Also love how the pool table scenes have that background noise. So creative!! Haha!!
These videos are so helpful and save so much time!
The day has finally come when CRASHCOURSE does a video on collisions!!! :)
So beautiful gradients at the end! Great job as always graphics team :D
Could an elastic collision be possible in a vacuum, where heat and sound are impossible?
*"Momentum, the Product of Mass and Velocity is conserved between portals. In Laymen's terms, Speedy thing goes in, Speedy thing comes out."*
Fivestrings uuuuh
Dear Madam,
There is a question which is iching my taughts since many days, that why speed of sound is constant??? Even though sound propagate by means of elastic collisions between molecules, speed of sound should depend upon the speed of molecules near the source of sound. Yes I have heard it already that molecule speed is directly proportion with the increase in pressure so the bulks module remains constant and hence the formula holds. But why then same phenomena is not observed in collision of two identical elastic balls, were the velocity of second ball depends upon the velocity of the first ball and hence the velocity of propagation of this collision also depended on the velocity of first.
I don't know who you are and I don't like the fact that you're not John or Hank Green but I will live with it since you have the most gorgeous accent I've ever heard
If tendency of an object to remain in motion is called momentum, isn't it sorta similar to inertia??
Inertia is the tendency of an object to remain in motion or rest while momentum is the tendency of an object to remain in motion :)
think of momentum as a special case of inertia
Momentum is inertia at a certain point when collision happens.
definitely gonna watch all ur vids this saturday lmao
Another great episode! Seriously don't understand how people can find these incomprehensible. You can't dumb it down much more, if you actually want to learn something.
Good
Why would velocity get halved as mass doubles in the magnet example? Mass and velocity are directly proportional?
i like her! she does a good job, plus she is funny.
marvellous video
What's the difference between inertia and momentum? Those words both mean the tendency of object to stay in motion, right? Don't they both have the same equation too?
Not really. Inertia has unique equations for different shapes (mostly variations of I =mr^2, such as I=2/5mr^2 for a solid sphere) while momentum has just the one (p=mv). The units for inertia are kgm^2 and the units for momentum are kgm/s. Inertia is a property of an object where it resists a change in motion, whereas momentum is just a statement of the velocity and mass of that object.
Taylor Arch Thank you for your answer!
You can't change inertia, but you can change momentum.
Assume mass is conserved.
WebGuy1000 - Domino Entertainment X-Men be fggcfff
WebGuy1000 - Domino Entertainment X-Men be fggcfff
awesome episode!!!Very informative
great app
Enjoyed your contribution to the programme about the battle of jutland on the bbc, shini. Very interesting.
Really liking CCP, too.
Isn't simple pendulum a one in which the bob is a point mass and physical pendulum any rigid body.
Okay, so I'm really sorry I'm writing this here since this might sound like somewhat of a stupid question, but can anyone please explain what she means when she says Impulse = integral of Fnet over time? To be honest, I don't really think I completely understand integrals yet- I watched CC's episodes on calculus, but I think all my tiny brain understood was that integrals were the opposite of derivatives, and that they were the area under curves. For some reason derivatives always made sense to me, so I guess it was more convenient for me to think of integrals that way. Anyways, I was hoping someone could please explain this a little further. Thank you :)
Can anybody please explain the math at 2:37? :)
This might save my GPA thank you so much!!
When are you guys doing fluid mechanics?
2022
You could have just said never.
Why'd you ask then? Lol. Its like asking if they're ever going to present post-doctorate crash courses. It's a show for high schoolers.
Well, it's not 2020 and they did fluid mechanics. Which means that you're an idiot. You really should reply when you really don't know the answer to something, it just makes you seem more stupid.
I'm sorry, my dear gentleman. I do not know what came over me to think such a thing. I truly thought that you meant an entire course on fluid mechanics but not just an introductory section. I bid you good day.
my doubt is when there is a perfectly inelastic collision in 2-D between 2 objects they dont really stick together but its mentioned in the video that they stick together ??
In the "real world," there's no such thing as a perfectly elastic or inelastic collision. There's a way to describe "how" elastic a collision is (which is the coefficient of restitution, if you were curious), but for an intro course, it's much easier to simplify the problems as perfectly one way or another.
I really love you :3
Love u Crash course!
1:15, *F* = m(d *v* )/dt = m(d *a* t)/dt = m *a*
Arwildo thats only gonna work if a is constant
Hello, Thank you, very interesting explanation.
How will the two balls in the pool table example be affected by the white ball having acceleration as opposed to deceleration at the moment of contact?
I actually find it easier to say that the centre of mass is the first moment of the mass distribution.
Momentum is not conserved in systems with drag (or other forms of friction).
Not to mention that in the examples with the magnets, they will accelerate towards each other and even then you will not have conservation of momentum. Even if one is inclined to perform this little experiment it will be quickly realised that the magnetic bead pair will most likely start spinning after it comes together.
lol
Momentum is conserved in systems with drag -- the momentum is simply transferred to the thing doing the dragging. If you're talking about air resistance, then momentum is transferred from the moving object to the air. If you're talking about friction, then the momentum is transferred from the moving object to the surface which is creating the friction. Often the momentum will end up getting transferred to the Earth, which will result in the momentum apparently disappearing -- but it hasn't disappeared, it's just that the Earth's mass is so large that any resulting velocity change is minuscule.
If the position of a body moving in a medium is monitored then momentum is not conserved, categorically.
Furthermore momentum doesn't have to be conserved in situations where you do not have spatial translation symmetry. In addition to non conservative systems as noted above.
In short to force momentum conservation you have to redefine the 'system' to include much more than one might have originally intended.
The case is still true for interacting particles, where momentum is, simply, not conserved.
Jason93609
You are being misleading. When physicists say that momentum is conserved, they mean it is conserved in a closed system i.e. where there are no interactions between your system and the outside world. This is *always* true, from the scale of galaxies, right down to sub-atomic particles. There are no known exceptions to this rule. You are talking about open systems, where the changes in momentum are not being wholly accounted for -- momentum is not conserved in that case, but then no-one ever claimed it was. (This holds true for energy too -- it is only conserved in a closed system.)
"Closed" systems are very special! And not the most relevant as well.
Do we add the mass dist. products?
should do a challenge question at the end of each episode
it aint a crash course..it feels like you have taken water drops from an ocean ...
not explained properly .many points are missing ...
In Russian momentum is called "impulse" and "impulse" is called "force impulse". It got me confused at the beginning, because every time I hear "impulse" I think of the momentum.
Is momentum the same thing as kinetic energy? Like how √x = x^(1/2)?
In Highschool, Kenya, we call it the Centre of Gravity, not mass. Not much of a difference, but it shows how different our curriculum is.
The moment you learn more in 9 mins watching a youtube video than you did sitting in a class you are playing thousands of dollars for.
Can't wait for mechanical waves
Anyone who would like a more detailed lecture on collisions, consider the videos on Khan Academy
www.khanacademy.org/science/physics/linear-momentum
The ball equation on when the ball hits the wall and changes its force in half a second. The equation itself was correct but the answer is 3.125. This is important for people taking the AP Physics C test, for they need you to round to the nearest 3 decimals.
Force is proportional to rate of change of momentum. Is that good enough for 1 mark?
Net Force*
Net force is proportional to the net change of momentum.
Force is proportional to the rate of change of momentum is completely true.
+Turhan Pathan yo you are right. I looked at an exam paper and even that is not good enough for them. It should go like this:
The net force on a body is the rate of change of momentum on that body in direction of the force.
nicesu
what's the difference between momentum and kinetic energy?
Momentum has a direction (it's a vector), and it describes the amount of "motion" something has.
It's good for figuring out how things move.
Kinetic energy is how much *energy* something has because it's moving. It has no direction, it's just a number. Because this is energy, not motion, you can change it into other kinds of energy, like heat, or electricity, or potential energy. KE is good for figuring out, for example, how much electricity a wind turbine will make, or how long it will take for something to slow down from friction.
Rhaegar19 thank you! that clears it up for me :)
Is Electrostatics coming up next?
7:40 more like 2/3 of the distance between the centers of the balls, not the stick (assuming the stick itself is massless). This might not be significant for a long enough stick and balanced balls, but it's significant when calculating a more skewed system. Like the center of mass of a solar system (which can be inside its star or very near its surface).
This lady is amazing. Wish she taught at my college. Would have done much better in Calculus and Physics in college and became a scientist instead of a lawyer . . . . plus she's got to be the best looking Physicist I've ever seen :-)
she's reading a script honestly I find her a bit distracting trying to prove a point about female physicists or something. THERE I SAID IT :P
she is ugly
@@user-nd1lx8co2g So just because a female has a career in STEM, she MUST be proving a point and furthering the feminist agenda instead of just pursuing something she's genuinely passionate about? Good to see misogyny is still alive and well.
no it's just that everything about this is fake she is reading from a script @@sarahholland5980
@@user-nd1lx8co2g But when Hank and John read from scripts it's no big deal right? They're not fake just because they're males? Okay, whatever you say.
Who came here after watching "Demonstrations in Physics" by Professor Julius Sumner Miller and can't stop laughing ?
Like if you did the same or maybe reply.
You didn't talk about coefficient of restitution
We have slow-comprehending brains (in that it takes our brain longer to translate what our ears are hearing) (autism) so the video "words" were too fast for us to comprehend but the photos / examples were GREAT!
0:25 ahaha remember in 2016 when 47 Super Mario fails was frustrating
now we can lose several thousand times in a row in fortnite
or maybe thats just me
crash course physics #9 got lost in the collision?
i'm looking for it as well.
Finally! A video I found an actual use for making legitimate use for RUclips's slow-down feature rather than only making people sound drunk. 😁
Impulse 101 gives you all the guns.
GAMER SPOTTED ON AN EDUCATIONAL CHANNEL (like me)
was impulse 99 the money one?
Where does the 25 come from in the impulse equation at 2:44? I understand it is an integral over .5 seconds but where does 25 come from?
thanks!
LOL this is actually a good video to help determine the possible outcomes of the upcoming Democratic National Convention.
I"m surprised by how much I learned from this video.
Is there a set of worksheets I can use to practice this skill?
shoutout to all the AP physics students who think they will understand all the concepts the night before the exam through crash course
Get it? Crash course- collisions?
Good episode! ;D
brains and beauty.
So we're just going to skip over fragmentation in collisions entirely? I thought that's why you started going into center of mass, but you kinda just glossed over that part like most high school physics courses because it's "harder" due to having to bring density into the mix which means having to lean on chemistry a little.
They are just doing the basics for now. Hopefully they'll do higher level physics after this one!
stupid lava sticks😂😂😂😂 0:24
Wasn't this girl Raj's sister on Big Bang Theory ?
Is kinetic energy derived from the integral of momentum? 1/2 V^2 looks like an antiderivitive.
5:00 *giggle like a little child* ---> Asuming the balls have the same mass
3:18 That isn't quite true.
"For this to be a true elastic collision all of the kinetic energy from the white ball would have to be transferred to the red ball."
For the collision to be elastic, the white ball doesn't necessarily have to transfer all it's kinetic energy to the red and come to a complete stop. The white ball can absolutely still have kinetic energy after the collision so long as the total energy of the system (the sum of the kinetic energies in each ball) is equal to the kinetic energy of the white ball before the collision. True, if the white ball transfers all of it's kinetic energy to the red, the collision is elastic. However, this does not have to be the case for ALL elastic collisions in this scenario.
Very true
If the masses are the same and the collision is elastic and the collision is not off-center (motion stays one-dimensional), then the simultaneous solution of the equation conserving KE and the equation conserving momentum results in a switching of velocities.
And "it's" isn't possessive.
Something's a little off here. She says impulse is change in momentum over time, but that would be mv/t, which is the same thing as ma, which is just force. Impulse is mv/t^2, or ma/t, or force per time.
Impulse is *just* change in momentum, and it's force*time. It has the same units as momentum (kg*m/s). It's the amount of momentum lost or gained.
*Force* is change in momentum over time (kg*m/s^2)
You're right, I was confusing impulse with jerk, which is acceleration per time. Force per time is equal to mass times jerk, and may or may not be called yank; I can't find a reliable source confirming that.
RICK FOR SEMI
I watch her videos and am suddenly sleepy cuz I lose track of the lesson much like real life physic the equations I can do but explanation is sleepy
you said in your video on newton's laws that according to newton's first law, an object would remain stationary (or in constant movement) unless acted upon by a force. A moving object that has momentum is moving at a constant velocity and thus has no acceleration, ergo should not be able to exert a force. However, that rolling ball is obviously able to move indiana jones if it collides with him. How is that?
where is philosophy?
Impulse, usually represented by a J
Physics: F*** spelling!
what a helpful video!!! thanks for the knowledge crash course
I gave my physics final today....now let's see how much I fucked up