Elastic and Inelastic Collisions - Physics 101 / AP Physics 1 Review with Dianna Cowern

[@NewMessage]

3 minutes ago, I had no idea I needed a giant Newton's Cradle.

[@ramgopalgupta3646]

your videos made my love for physics much deeper !!!! That it has become so deep that it is more than the depth of pacific ocean !!!!!

[@eduardopekurned1505]

warm thoughts on stretching balls of panspermia !!!likey likey

[@reesespieces3884]

I would love for her to be my physics teacher. It only makes sense when she does it lol.

[@serenaterry387]

I heard about you when I saw you on the saint Jude's live stream and I thought your channel would be interesting, so I subscribed and I don't regret it at all.

[@snags3067]

Love your channel, my 10 year old niece adores you and you make her love for math and science even stronger 🤗.

[@bryandonahue8302]

As an Aerospace Engineering major, I can't say any if this is new to me... that being said I'm seriously loving this series. Thanks for making math and science so interesting and engaging.

[@outresru7751]

you're teaching everything my school is trying to cram up us about. thanks, love you!!

[@PapaFlammy69]

She attacc she protecc but most importantly, she collide(ecc?)

[@TM-vh1qg]

She *smacc Would've been better

[@joke34]

why is a shiba inu viewer here? 😂

[@kawaichanx3]

Papa's here

[@portobellomushroom5764]

These videos are coming out literally the day after each of my class's unit tests on each of these topics 😂

[@FlyingSavannahs]

Oh fate, thy name is cruel. Let's to air hockey!

[@kianstrenn]

I’m sorry! They’re still helping me with my units 1 year later!

[@nomeaknat]

Out of all the videos I make my nephews and nieces watch, yours are what grabs them. It tickles me that they are interested in science.

[@eccentricOrange]

3:40 Good job! You're getting better with the parabolas of the markers!!

[@RobertSmith-pw9io]

Another Great class Professor ! I am so glad that you are showing all of these, instead of being hidden away teaching in some old University ! Thank You!

[@FlyingSavannahs]

Yeah, like that Einstein guy at Princeton. Who ever heard of him?

[@captainbeaver_man903]

I wish this kind of video was freely available back when I was in highschool. Its never too late I guess, nearly 15 years later.

[@randomsaloom7238]

exactly how my teacher explained and its nice she explained yesterday right before this vid

[@kavionic279]

Love your enthusiasm when explaining things :-)

[@craigvdodge]

Dianna “Crocodile” Cowern: “That’s not a Newton’s Cradle. THIS is a Newton’s Cradle!”

[@John.0z]

The one The Mythbusters made out-did that backyard one too. They built it on a really huge scale, in an old dry dock. By the time you have balls weighing *tons* the friction in the system results in non-linear behaviour.

[@FatManWalking18]

now THIS is a Newton's Cradle kzbin.info/www/bejne/haakXq2ki7KMaas

[@John.0z]

@@FatManWalking18 I found it a most interesting example of how many things in physics do not scale. Later Brian Cox was talking about how really tiny flying insects are operating on a quite different lift principle, and operating in a realm of energy fields that makes it like flying through a thick medium. Scale is an important consideration.

[@math_the_why_behind]

It's so cool that you make gigantic versions of objects, such as the huge Newton cradle in this video, the bowling ball that almost hit your face, and the human-size Atwood machine. And now you have cats in addition to cows!

[@sooryasijin3343]

When she says the name of this series.... Reminds me of agent Coulson saying "Strategic Homeland Intervention, Enforcement and Logistics Division" 😂😂😂

[@preetityagi4909]

kzbin.info/www/bejne/hXnUlnumnNqJftE

[@avidnongetit8710]

Such a great comparison! I never felt so nerdy+COOL! Thanks 😎

[@TGK06]

Me its like waiting upto midnight to watch your videos 😀physics is love

[@samedwards6683]

Thanks so much for creating and sharing this educational and entertaining video. Great job. Hope that each day you are feeling better than the day before 🙏

[@Alexander_Sannikov]

I understand that 101 physics education is important, but I've subscribed to this channel for more advanced and lesser known stuff.

[@charleediaven6278]

We once played handball with a superball in a large shower room. Tile everywhere. The superball can be spun when hit. It is hilarious how fast the ball goes and the wild way spin changes it. Also try flicking a wedge shaped piece of cork, like the old fashioned ones from wine bottles. The cork is the ball. The batter has stick and stands the appropriated distance. The cork can be flicked with the thumb or spun like a baseball with hand and wrist. The thumb flick gives best spin. The cork at about 10 meters can curved about 1/3 to 1 meter. ( broom handles work. )

[@AB-ye7bw]

I saw the two index finger balance of a yardstick demonstrated years ago on Mr. Wizard ! Still use to this day for finding the approximate center of pvc pipe. Works every time.

[@FlyingSavannahs]

Dianna and I have an ongoing pedagogical debate about how to demonstrate algebra in intro physics. Well, it would be a debate if she ever replied. What all the other train car collisions will look like viewed in one equation: Much of physics study involves learning how to "read" an algebraic equation that describes some phenomenon. What is the formula telling you? How does it behave? We have a great example from the colliding train cars to look at. If you hold off before plugging in numbers and manipulate the equations first (that's the debate!), you can visualize the entire domain of final states that can result after the collision. Think of varying the masses of the train cars like a volume slider controlling your soundtrack from the movie π. With a little algebra you can create a comprehensive equation that allows you to see everything at once. Let's split off into a parallel universe at 5:03 and investigate these specific momentum equations a little further. (In this universe the element Diannasium has the curious property, when under bombardment by positrons, of sending the experimenter back in time to the Solvay Conference of 1927.) Here Dianna equates the initial and final momentum equations, because the momentum is conserved, to get m_1 • v_i = (m_1 + m_2) • v_f Then m_1 v_f = --------------------- • v_i m_1 + m_2 This is the equation she says is useful to investigate. She plays with varying the masses to see how the final velocity relates to the initial velocity of the oncoming mass. For m_1 = m_2 she gets v_f = (1/2) • v_i like after 5:03 in her original universe. Check! Now for the approaching rail car much less massive than the stationary car containing 42 kilotons of pure Diannasium (enough to send the entire MIT ΣΠΣ chapter and two faculty advisors to early 20th century Brussels), the denominator will be much larger (and ≈ m_2) than the numerator, so the final velocity will be small. Sanity check: Think throwing an egg against President Ivanka standing on a stationary hoverboard. She wont budge much. She never has. Check! Conversely, when the oncoming mass is much larger than the stationary mass, the contribution of m_2 in the denominator is negligible compared to m_1 and the quotient will be close to 1. So the final velocity of the joined masses is darned close to the first mass's velocity. Sanity check: Dianna asks you to remember when the Titanic hit and dragged along Admiral Dawson's yacht in New York Harbor and the cruise ship didn't even notice? Check! Then she tells you the algebraic form of this mass coefficient is commonly seen in physics and math, thus it is highly practical to know the behavior of this term at these special points and boundaries. Relate it to your commonsense knowledge of what things do in the world when they collide inelastically. This can make the formula "come alive" for you if you understand it on a visceral level. Dianna expounds that now you even have enough information to mentally visualize and sketch a plot of this coefficient based on the ratio of the masses. Is that cool or what?!?! Then I enter the studio and say, "In physics, the beauty of its formulas is in equal measure to the power of its computations! Let's to shuffleboard!!!" and an engrossing conversation ensues. Later: Ok, let's get back to the original universe with this...switch here.....zzzwang! What the? -- "Guten Tag, professor Einstein! Bonjour, madame Curie!"

[@avidnongetit8710]

Thank you for allowing us to come and learn physics. Quietly without pressure from teachers and students who Excell in mathematics 😎

[@edshelden7590]

I really like the end explanation of particle physics.

[@jodhweijoundica3453]

she's like "nooo paper, i'm not ready to explain the dynamics of springs!"

[@janpr9712]

12:00 The math is not all that difficult, however, it produces two valid results. Either v1’ = 0 and v2’ = v1 (what we expect) or v1’ = v1 and v2’ = 0 (ball one misses ball 2).

[@aishamoln.a1428]

OMG... You are just trynna help me complete my entire physics course of class 11th.... Thankyou Didi..❤️

[@mickeygarlock4611]

That's complicated for me as my dad and brother had a total time on the railroad of 85 years :) I no nothing of the specifics of Physics (but am learning from you) I just knew half because of seeing it so many times, but I never knew the physics of it. I would say it has a lot more importance in outer space.

[@jaysartori9032]

I love Physics and Science all of that stuff! A body in motion stay in motion unless acted upon by a outside source?

[@jlpsinde]

Hi, yes. If net force is zero the velocity stays the same.

[@apescape3223]

Wow this felt really authentic. Chemistry and physics really have so many similar concepts.

[@FlyingSavannahs]

It's no surprise that there is a Physical Chemistry field of study.

[@AthAthanasius]

If I've figured it out correcetly, the reason that when you release *two* Newton's Cradle balls at the same time from one side that then two come up/out the other side is exactly because that's the only way you can conserve both momentum and kinetic energy. For only one ball to 'react' you'd need twice the velocity to conserve momentum, but you'd need sqrt(2) times as much velocity in order to conserve kinetic energy, so that won't work. I didn't do the rest of the detailed working out to see why it's two balls reacting with matching velocity of the two incident balls rather than, say, the outermost ball going a bit faster than the inner one of the pair. But, I think that's ruled out because any ball will only be accelerated whilst in contact with the previous one, so there's literally no way to get the outer one going faster, only, at most, the same speed as the inner one. Also it can't be slower, because then the inner one would still be driving it... until they match.

[@taboosaboo]

Elastic: MaterialReturn. 2:16 Pool balls elastic? Sure.. they return to the pockets, or the rack. Due to Forces of Interaction.

[@hellcolik7056]

It's been a while a have not come to this channel and it makes me smile that Physics Girl seems so happy to talk about science. It seems so strange that I wonder if she is genuinely like that or if it's a commercial based behaviour (I already know the answer but I can't help but wonder)

[@Ktulu789]

So... you need less energy to accelerate two wagons to 6m/s than to move one at 12m/s? Forget about collisions, just a simple motor on each.

[@En_theo]

Yep, something seems illogical there. The loss is certainly not the heat of the collision, it's more about a moving object pushing from the same referential since the beginning.

[@yoavboaz1078]

about in-elastic collisions: if some of the energy is lost to heat why dont some of the momentum get lost to heat?

[@lidular]

Both in high school and University physics 101 I found this to be the hardest subject

[@stephenbenner4353]

Well, I can’t say that Dianna wasn’t trying to make physics interesting to an English major like I was in college. Two Shakespeare references is definitely a plus. It helps to remind us that even geeks are people too.

[@patrickskramstad1485]

I am not sure if this was brought up before. But, I was told the reason why the white Q-ball was able to return to the same pocket because of say a scratch, was because the diameter of the Q-ball is smaller than the other ones.

[@GooogleGoglee]

Technically after the 2 masses impact against each other (in the example of the 2 trains or cars) the final velocity will be less than 6m/s (less than the half of the original speed v1) because good part of the energy will go also wasted in sound and heat. 12 meter per second is a good speed!

[@Valdagast]

_When two worlds collide_ _The anger and the pain of all those who remain_ _Two worlds collide_ _Who will be left alive_ _No place to hide when two worlds collide_

[@mathsandsciencechannel]

Lol. Learn more on maths and science channel and sub for more

[@pratikrajchandekar8319]

You are best I really understand everything you teach. Thanks sister 😊☺☺

[@scottthomas6202]

An elementary school science teacher I had used Hot Wheels cars and track to demonstrate a variety of principles... something children could relate to ..

[@ImSYD]

Just Waiting for AP PHYSICS to redress my concepts!😄

[@Vlow52]

Thanks for the video, Dianna. Could you consider making a more detailed video about ball collision in the pool? There are 90 and 30 rules of deflection after hit and it souls be interesting to understand the physical reasons for that

[@BillMSmith]

I've really been enjoying relearning, and learning, with this series. However, early in this video I had one of those bad classroom moments. When presented with the problem I realized that If I had memorized the previous equations I could solve this, but I hadn't. Thanks for making me feel like a teenager again. I guess. 🤪

[@muhammadhamza4494]

I really like the way she explains the concepts

[@mathsandsciencechannel]

Same here.Learn more on maths and science channel and sub for more

[@gab.lab.martins]

18:47 "What happens when you have balls of different masses?" That's actually pretty normal. Also of different heights.

[@turpialito]

Just differentiating between elastic and inelastic collisions... wish my HS teachers would have been as clear as Dianna.

[@techhelp1941]

Is there any perfect elastic collision? What do you think Diana?

[@dij8nz]

So, this question/statement is based on the premise that sound is a form of energy. Which it is, right? As is always the case with your examples, let's take friction out of the picture. :) If I understood correctly all those years ago a Newton's Cradle slows down over time because some energy is "lost" in the collision through sound. Sound doesn't travel in space (a vacuum); although I may be wrong with that rule too. So will a Newton's Cradle run longer in space because there is no perceivable sound? (ignoring the friction of air thing) Just because we can't hear the sound doesn't mean it isn't generated, right? It just doesn't travel any distance. I'm just following your idea of taking things to extremes. If we start a Newton's Cradle too far away to hear it the "loss" of energy through sound still applies. Please explain all the ways I am wrong with these questions/statements (I'm sure there's a few).

[@jules665]

How convenient for me. I am learning this in chemistry right now

[@BG-xq5jg]

Clapping hands elastic or in elastic If the mechanical coupling device fails would the kinetic energy transfer be greater on the second car🤔🤔🤔

[@junak777]

Reminds on Djed pillar. Shock wave flower. Where some areas instead of taking losing speed due to back forths motions among (balls on string of Newton cradle) ionic pillars are bouncing of barriers of next iteration therebt gaining it.. Pipe or that lamp that has connecting switch ropes. Wormholes. There is a gif of a huge big man jumping in water with ball, creting negative sling catapult bubble like that bounce among big and small balls pushing ball he was holding way in the air. Wow! Indeed. Thanks Diana girl of Physics! :-)) PS I could extrapolate and abstactly say that col-lision has cold color column colar ..COL part ..anyways that is photonic informational grid net web , something yes, that explains all kind of couplings among photons and electrons, among sphere and collase into Riemann Avatar flower of light torpedoes parking places on those latticies. Kinda. :-)) Plucking the string and reverbs.

[@louieluigi9048]

⌚is time colliding into something?

[@pjpcarv]

Newton Craddle - Lift one ball and release, one ball comes out the other side: Lift two balls and release, two balls come out the other side: Lift three balls and release, three balls come out the other side (the ball in the middle keeps moving): Lift four balls and release, four balls come out the other side (two balls in the middle keep moving): Lift five balls (all) and all five balls come out the other side, duh!

[@jero528]

Wow!? Clearly the best one ever!!😎

[@slayer7003]

Wanna fall in love with Physics, follow this girl!

[@elraviv]

Thank God that when I studied it, we called an inelastic collision - a plastic collision. this is much less confusing. "plastic" reminds me of plasticine, you can not have an elastic collision with plasticine. LOL

[@mathsandsciencechannel]

She made it easy. Learn more on maths and science channel and sub for more

[@En_theo]

Could you explain how we got the kinetic equation K=1/2 (mv²) please ? I never got how they derived that one, it's not even explained in Feynman's course.

[@TheTotallySaneDane]

It's based on the fact that F=ma (mass times acceleration). If you accumulate this acceleration over a certain timeframe you get a velocity. Assuming that the acceleration is constant, this is the same as integrating the acceleration with respect to time. If you imagine the graph of this, the velocity is linear with respect to time, and should therefore be a straight line starting at 0. This is just a triangle, and the triangle has the dimensions of m/s^2 and s. Multiply these together and halve it (since it's a triangle) and you get the formula in question: F = 1/2 (mv^2).

[@rivertam1921]

I wonder how having very little mass like a neutrino works with it's collisions being rare and with specific objects like heavy water atoms. Or how waves of a photon in the double slit can be a wave colliding into the waves if the atoms making up a detector. Are the elastic or inelastic sticking and leaving mass or transferring energy to be detected as a certain point.

[@orfeassiozos1575]

Why did we never learn the negative relative velocity trick for elastic collisions?! It looks so good and helpful!

[@fantazee5917]

do you think billiard is perfectly elastic collision, or just elastic collision?

[@jamesjohn2537]

Hi, Diana, that is amazing keep it up! I love your explanation

[@TreeLeaf01]

Great video! Please keep up the great work! Been a while since freshman year in college... Isn't the derivative over time, so 1/2*Kg*m/s^2, not 1/2*Kg*(m/s)^2? That would imply that the ratio was shared between meters and seconds (m::s), not m::s^2 Think you say this even as you're talking about it, but in comparison to the elastic, the square is outside the ratio notation...

[@Akshit-te7gx]

That was the greatest day of my life when i accidentally entered to this channel

[@preetityagi4909]

kzbin.info/www/bejne/hXnUlnumnNqJftE

[@vasiwasi4899]

what do you call your bookshelf?

[@roytee3127]

Physics trivia - Descartes tried to develop a theory of inelastic collisions where the particles were infinitely hard and didn't bounce but didn't smoosh either. His effort was a disaster. Ended up with eternal vortices or something. Sometime I'll try to find a link. (My apologies - it's been a long, long time since I studied this.)

[@En_theo]

That may be interesting, I know that both Newton and Descartes disagreed with the E=1/2 m v². The equation was different back then, but they thought the energy should evolve linearly (it should not follow v²), it took almost 1 century to establish the kinetic equation. I still have doubts about this, e.g. here Diana calculates @7:50 that the energy is half of the momentum and says "it's ok, it's lost in heat in the collision". Since momentum has been calculated without considering such losses (and remember that we took the Vfinal from the momentum equation into which there is no loss), that explanation should not hold and it should not be just 1/2 of loss since it depends on the type of collision (hard material or not, etc.).

[@roytee3127]

@@En_theo Gotta agree - the v^2 aspect is strange. I hope to get back to this soon, after taking care of more immediate business. Meanwhile, this goes into Decartes' physics. (But inelastic collisions are a minor corollary.) plato.stanford.edu/entries/descartes-physics/#SpacBodyMoti

[@roytee3127]

There's one statement in the article that I take exception to, but more later.

[@En_theo]

@@roytee3127 Thanks, gonna read that as soon as I got the time.

[@roytee3127]

@@En_theo Glancing at the article, it appears to start from Descartes' philosophical premise that all volume must be filled with matter of some kind - and extreme form of "nature abhors a vacuum". So "space" is filled with particles that are constantly pushing each other around; no room for a bouncy elastic collision to take place. That's my impression from a quick read.

[@vinay9477]

Pls anyone explain how to get to the derivative...I wanna know why we have to use it And how did we get there...

[@preetityagi4909]

kzbin.info/www/bejne/hXnUlnumnNqJftE

[@hemamauryamaurya2737]

I was waiting for this video only. ☺️

[@preetityagi4909]

kzbin.info/www/bejne/hXnUlnumnNqJftE

[@SantiagoMejia]

I've never been so early to a Physics Girl Video.

[@atharvsharma2539]

Same

[@mohemmedilham3854]

Me too

[@herambpatilofficial]

I loved the introduction till 1:02 , video is also great 👍

[@FlyingSavannahs]

I don't wish to be the bearer of bad news, but if you didn't know, Hamlet doesn't end so well, either. Let's to ten pins!

[@mathsandsciencechannel]

Splendid. Learn more on maths and science channel and sub for more

[@kriti4621]

love ur passion for physics

[@MGD313]

Stringer Bell taught me everything about elastic and inelastic goods.

[@imamastermind]

Hey, a request-Can you do a video on work done? Thanks a lot love your videos clears all my concepts!

[@preetityagi4909]

kzbin.info/www/bejne/hXnUlnumnNqJftE

[@sherrineal3973]

What was going on when the paper you wrote on wanted to roll back up????

[@shahzadmaqbool9649]

Can you guide me about what is isotope shift experiment in Nuclear physics..

[@mathsandsciencechannel]

Okay. Learn more on maths and science channel and sub for more

[@preetityagi4909]

kzbin.info/www/bejne/hXnUlnumnNqJftE

[@shahzadmaqbool9649]

@@preetityagi4909 hmmm

[@bromanl1362]

Let's say you have a 1 kg mass moving to the right at 20 m/s that collides with a stationary 2 kg mass and bounces off to move to the left at 10 m/s with the 2 kg mass moving to the right at 5 m/2. The time of collision is the same for both masses, but the net force is different since the impulse or change in momentum on the 2 kg mass is 10 kg*m/s and the impulse or change in momentum on the 1 kg mass is -30 kg*m/s. How does this figure or how is momentum conserved with the momentum lost by the 1 kg mass not being equal with the momentum gained by the 2 kg mass? How can the net forces be different?

[@osmosisjones4912]

I think rocket should be on a ship's center of mass . exhausted at back still an option but moving the center of mass would be much more full efficient

[@michaelsommers2356]

No, it would not be more efficient. The rockets would also have to constantly move because the center of mass will change as the fuel is used up. And the exhaust from an engine part way up a rocket will destroy the part of the rocket below the engine.

[@atharvsharma2539]

What if you have a circular Newton cradle, will you keep storing energy

[@preetityagi4909]

kzbin.info/www/bejne/hXnUlnumnNqJftE

[@arsonor]

One clarification, an elastic collision requires complete conservation of mechanical energy. That’s important for AP Physics 1 students to understand if asked to verify the nature of a collision.

[@arsonor]

This comes into play in resolving collisions in two dimensions.

[@shreyanbasuray1033]

Do more videos on Quantum physics like you used to, Newtonian is so limiting !! ☹️

[@shreyanbasuray1033]

@Avisha M Just basing my comments on her previous videos. Been her superfan since the beginning of her channel. Although she's gonna do what she feels right and my comment won't affect her much either, still I'll keep in mind what you say :) Thank you.

[@preetityagi4909]

kzbin.info/www/bejne/hXnUlnumnNqJftE

[@basaralhawi8475]

Its like hold the energi and remove the energi back

[@ramy8338]

This video is very informative

[@preetityagi4909]

kzbin.info/www/bejne/hXnUlnumnNqJftE

[@GreeceUranusPutin]

A little over a minute in and no happy ending to be expected. Dammit, I came here looking for a happy ending!

[@gigglesvids3561]

I've always wondered what causes super-bounces on trampolines! :D

[@03whiteSVT]

Mind blown 🤯

[@nikunjdeepupadhyay5058]

Mam I am Nikunj Deep your obedient Indian student it's my humble request kindly make video on radioactivity

[@SolarasNaracott]

What if the Newton's Cradle was really big? Is there a size where the last ball doesn't recieve the energy and momentum of the first?

[@aliciazwilkinson]

Not in an ideal situation of no air resistance and no loss of kinetic energy, but in real life the the balls slowly loose kinetic energy and you can see this as their height decreases until eventually the collisions stop.

[@edwardlucero2120]

What I learned; Party Tricks!😂

[@RedmarKerkhof]

Hehe I made a video of a Newton's cradle I had, like... 12 years ago? It was one of the few clear videos of one of them on youtube at the time and even the University of Texas contacted me asking if they could use it for demonstration purposes. The audio has somehow completely gone down the drain over the years though. Ahh good times.

[@itsreeah2663]

Ur the best physics girl

[@trampfossil9760]

would you do a program on NANO PYYSICS?

[@aritramondal8901]

Enjoyed very much....

[@nikoscosmos]

In the case of the balls hitting the ground surely an external force is being imparted into the system?

[@michaelsommers2356]

You can consider a ball bouncing off the ground as a collision between a teeny tiny ball and an enormously large ball (the Earth). Yes, there is gravity between them, but if you look at the velocities immediately before and after the collision, that can be neglected. One of the most important things that a physics student needs to learn is when and how to approximate.

[@FlyingSavannahs]

@@michaelsommers2356 I used to be right on target with my approximations but now I'm a little off.

[@michaelsommers2356]

@@FlyingSavannahs There's nothing worse than an approximation that isn't exat.

[@jlpsinde]

Very good video!

[@anthonyguerrera191]

Can u do AP Physics C Electricity and Magnetism content

[@konstantinkurlayev9242]

Thank you!

[@martf4701]

WOW... 7h and more than 100 comments after you've put this video online, still NO reply/answer to anyone by her yet...