Open vs Closed Systems and Total Mechanical Energy & Momentum (AP Physics 1)

[@simplyshravya3925]

Saw that this was uploaded 5 minutes ago and clicked instantly because I REALLY needed this! Open vs closed systems was never really taught in a detailed way in my class. Very helpful video, thank you!

[@themathandphysicstutor]

Glad it helped! Im up late grinding too. Share it with a friend!

[@shashanksreepathi7184]

@@themathandphysicstutor can you share the document by chance. So I can review it for the Exam?

[@akalajones3719]

These videos you have been uploading are really helpful especially for the majority of kids who don't have good physics teachers because it is a very hard subject to teach. Thank you!!

[@themathandphysicstutor]

You are welcome!

[@ananyaanair917]

Oh my gosh! It's like you are a mind reader when it comes to the topics you choose! I so needed this in my life right now!! Thank YOU! And woohoo - 1,000 + Subs - congratulations! Glad to be learning here!

[@themathandphysicstutor]

You are so welcome!

[@jessielindsey9128]

Thank you!! I’ve had the longest time comprehending this and haven’t been able to understand any other explanations other than this one

[@themathandphysicstutor]

You're very welcome!

[@spammyspammo2513]

HOLY SHIT you are actually an amazing teacher and explainer. I'm sure you helped ease the lives of thousands of students just by posting your last minute cram videos. Thank you so much for what you have done, I actually love you.

[@themathandphysicstutor]

Thank you so much for the kind words! Good Luck to you!

[@chriszovko4128]

Thank you so much for the extra help and all these videos. My friends and I had a discord server of 30+ people and your videos were the best source we used for review and to actually understand physics --- You really helped us out today; we felt a lot more confident because of you -- Thank you!!!

[@themathandphysicstutor]

Chris that means the world to me! Thanks so much!

[@EgoTeach]

Thanks a lot mate. I am 15, and I am studying for AP Physics. I came across your video regarding Open and Close system and it helped me a lot. Keep up the good job mate.

[@boss4635]

I would just like to thank you for all that you have done to teach physics in the past few weeks. I think because of you, I understood every concept on the AP test and was able to answer it to the best of my ability. From the bottom of my heart, I would like to again thank you for what you have done in the last few weeks. When I take Physics C next year, I hope you can still produce content for that class. Please continue to do what you do best. Take care.

[@themathandphysicstutor]

There will be C content next year!

[@themathandphysicstutor]

Thank you for sticking with me after the exam.. although you may never need physics again, staying subbed tells KZbin it was good stuff and other can benefit! Take the SAT 2! You'll get an 800 if you come with me!

[@krishnannarayanan8819]

Holy crap, it finally clicked with this video! Thank you so much! My teacher didn't formally explain all of this, so this is very helpful for me!

[@themathandphysicstutor]

Awesome. Please share

[@journeykeen5471]

I wish you were chosen for the official AP KZbin channel.

[@themathandphysicstutor]

Maybe next pandemic 🤷🏻‍♂️

[@beckhammountford5704]

Hey man I've been watching your videos all night and a lot of stuff clicked that I haven't understood for a while. You have a great way of explaining things and I hope your channel keeps growing because I would love to see you as a big teacher on youtube Keep up the good work!!

[@lailasyed2078]

I would like to say I just took the AP exam, and this video helped more than anything, even doing practice problems. Thank you so much man! I feel like I actually did well for once.

[@themathandphysicstutor]

Thats great news!! Glad you crushed it!

[@samyang536]

great vid! Glad you have reach 1k:) I been a real one, stuck with you since you barely had 300 lol. Keep up the good work and these will be great help on thursday! Cheers man

[@themathandphysicstutor]

I appreciate it!

[@c_berb2726]

This video taught me more than my physics teacher could in a week. Thanks!

[@themathandphysicstutor]

Glad I could help!

[@gregtime]

Excellent video. Really helpful for last-minute cramming.

[@themathandphysicstutor]

Glad it was helpful!

[@Mia-kz4hz]

watching this before my ap today; so helpful!

[@themathandphysicstutor]

Good luck

[@sashasychov7902]

genuinley explained really really well. I understood right away. Thanks a ton.

[@themathandphysicstutor]

Glad it helped!

[@SK-tr1wo]

Physics 1 gang, YOU GOT THIS DONT STRESS DO YOUR BEST

[@msb9664]

OMG THANK YOU SO MUCH 😭😭😭😭😭😭 you teachers are such a blessing in our lives

[@zbzb923]

MSB hey did u watch the live session if u did can u send me what u have from it cause I couldn’t attend the livestream

[@themathandphysicstutor]

Thank you!

[@sambaggins8163]

This literally helped so much. It makes so much more sense now. Thank you!

[@themathandphysicstutor]

You are welcome

[@richmakino1616]

Very Good!

[@themathandphysicstutor]

Thanks!

[@sayansisodiya527]

Can you link that document that explains the difference between the open and closed systems? It seems super helpful. Thanks for the clarification video, too; it was super helpful!

[@themathandphysicstutor]

I dont have a website I am sorry. But feel free to just screen shot it!

[@sayansisodiya527]

PS I think I might have been your 1,000th sub! Congrats and thanks for all the great review content!

[@Michael-ox6ex]

A big thank you from a student that is about to take the exam in no less than 2 hours from now

[@juiceontheloose123]

holy crap you're a lifesaver. I appreciate this soooooo much!!

[@themathandphysicstutor]

Thank you for the kind words

[@poojarathaur9906]

Hi! Your videos are so helpful! Thank you so much! Are you still planning to conduct your live session today, May 13, at 8:00 EST? I was eagerly waiting for it :)

[@themathandphysicstutor]

SOrry for the delay

[@mayalobo6137]

Thank you. This was explained really well.

[@themathandphysicstutor]

Thank you for the kind words

[@ananyaanair917]

Can you please continue to make videos for folks like me taking the test in June? Your videos mean a lot to us!!

[@themathandphysicstutor]

Yes!

[@ananyaanair917]

@@themathandphysicstutor Thank you so much! You are a life saver!🙏🏻

[@ananyaanair917]

@@themathandphysicstutor Also, I want to support you as much as possible, so I subscribed to your other channel too!

[@stephaniezoltick2976]

THIS IS SO HELPFUL! THANK YOU SO MUCH

[@themathandphysicstutor]

Glad it helped!

[@AlboonS-zy7su]

W energy coming from this guy. Bro Ive been confused on this for a while, thank you for properly explaining this 💙

[@themathandphysicstutor]

Happy to help

[@annazhou752]

To explain our reasoning, should we mention the types of energy that each system experiences? Eg. KE for System 1, EPE and KE for system 2, and KE and GPE for system 3. (btw congrats for 1k! only discovered the channel yesterday but ever since then I've been watching nonstop)

[@themathandphysicstutor]

You should mention the most amount of correct information as possible in the time allowed

[@2012Bcam]

YOU REACHED 1K been here since the hundreds lol one day til testing!! 😎😓

[@themathandphysicstutor]

Thanks for the support!

[@alanxia1359]

you're a literal god.

[@themathandphysicstutor]

Nah man.. im a regular guy that by some miracle was good at physics and loved having summers off!

[@AJO2003]

Just finished the exam! Wanted to say thank you. You helped me a ton with prepping for the exam

[@themathandphysicstutor]

awesome!! You smoked It??

[@AJO2003]

I feel pretty confident :) it felt much easier then I was expecting

[@smayannirantare8585]

You are a life saver! Thank you so much!

[@themathandphysicstutor]

You’re welcome. Please share

[@aberrxnt3641]

Great video, I know you have done alot of videos on harmonic motion and was wondering if you know any great study materials for SHO, and rotational motion in general? units 6 & 7 were a little odd to learn online:)

[@themathandphysicstutor]

The College Board website is the only resources next to this one that I recommend.

[@timnguyen885]

Hey sir. Would you post a video about the solution of our exam after we took the test??? (Your channel is really helpful btw)

[@themathandphysicstutor]

Yes. I think there are gonna be many different questions given. I don’t think everyone is getting the same one. But I’ll post solutions to anything I get

[@edbrains9742]

Hey, is there any way you can please please make the stream you just did not private? It say's that it's a private video now. I was watching and taking notes so I was a bit behind and it cut off right when you were explaining something... Is there any way you can make it public? THANK YOU!! It helped me a lot!!!

[@themathandphysicstutor]

I made it live until midnight

[@edbrains9742]

@@themathandphysicstutor Thank you!

[@ambercooper5414]

I know this is a vertical spring scenario - so I think i overthought it. When do we ignore gravitational potential energy (like what system)?

[@BradenSchlimme]

Thanks for all the amazing videos! You made my exam so much easier🙌🏼

[@themathandphysicstutor]

Happy to help!

[@supervideomaker33]

Hey quick question at 4:10 in the block system Only, with the outside force of gravity acting on it, wouldn’t mechanical energy decrease since kinetic energy is decreasing? (Fg in negative direction?)

[@felixgong22]

THANK YOU SO MUCH! I just finished the exam and you helped me so much! I would have failed without you!!!

[@themathandphysicstutor]

awesome!! you crushed it??

[@felixgong22]

Math And Physics Tutor pretty much!

[@edbrains9742]

At 4:10, you said the mechanical energy increased for the only-block system. Though the potential energy decreased, it gained kinetic energy. Did the increasing kinetic energy overcome the decreasing potential energy to make an increasing overall mechanical energy? Am I just misunderstanding the concept that any type of positive work means an increase in total mechanical energy, even if PE decreases but KE increases? In addition, at roughly 3:36, you said that the total mechanical energy of the block only system increased because the net force is upward. Doesn't gravity do negative work on the system too, as it acts parallel but negatively? In this case, would the positive work of the spring on the mass overcome the negative work of gravity to get a positive net work? Thank you! Congrats on 1000.

[@themathandphysicstutor]

Yes, and Yes

[@nicoscialdone2707]

Thank you very much, this was a very big help

[@themathandphysicstutor]

Thank you for the kind words

[@sheeesh5937]

Thank you so much for your videos! I think I actually did good on my physics exam, and you helped me a ton. You're a real one. Will you be making physics C videos?

[@themathandphysicstutor]

Yes. Next school year there will be C videos for sure! Next focus will be SAT 2 Physics in Aug and Sept

[@tyleroneil9605]

Just wanted to stop in and say thanks again for all of the help you’ve provided to many kids including myself since this exam format change. You helped me understand many concepts and go in to the test with confidence. Now that it is done, I saw that you are willing to go over the correct solutions to the FRQs. Do you know when college board will release these? Also- how much time after the prompts are released do you think the video will take to be out?

[@themathandphysicstutor]

Asap

[@saratulchinsky2982]

This was really helpful! But what about the force of the ceiling on the spring? I get that it does no work, but isn’t it still an outside force? Also, what if you had two outside forces that completely balanced each other- is the system still open?

[@themathandphysicstutor]

its not "outside forces" its "outside NET forces". The forces acting outside the systems are equal then Fnet would be 0 and the system would still be closed

[@mahonishizumi6276]

Perfect

[@themathandphysicstutor]

I got you!

[@mahonishizumi6276]

now I just need to find a way to let my brain use equations creatively and not panic when a certain equation doesn't work out.

[@dominatorspyder4474]

This guy is god level

[@themathandphysicstutor]

Thank you for the kind words

[@ananyavangoor6741]

Are you not doing an AP live anymore?

[@zbzb923]

Hopefully he will do, I am also waiting, he said in another comment 45 minutes ago he is trying to work things out, so optimistically everything goes right

[@themathandphysicstutor]

I am.. figuring it out

[@themathandphysicstutor]

stand by

[@spammyspammo2513]

Once they are released to teachers, do you plan on reviewing the 2020 exams we took yesterday?

[@themathandphysicstutor]

I will the day they are released

[@spammyspammo2513]

@@themathandphysicstutor sorry for asking again, but do you know around when they will be released?

[@gabrielapedreros4868]

Your so amazing. Can’t believe I found this account the day of the Ap Physics exam :(

[@zbzb923]

Gabriela Pedreros hey if u watched the live session can u send me what u got cause I couldn’t be online that time

[@themathandphysicstutor]

You got this!

[@themathandphysicstutor]

KZbin blocked the live stream because of idiots in the chat spamming and using inappropriate language and hate speech. Its not coming back

[@rishityokananth2069]

Thanks for your help man, just wanna pour love for your grind. I feel great about the test bc. of your explanations.

[@themathandphysicstutor]

Glad to hear it! Thats awesome!

[@ying.jye_li5934]

the ap exam was a breeze thank you so much for your videos definitely would've failed without this channel

[@themathandphysicstutor]

That means the world to me!! you smoked it??

[@ying.jye_li5934]

@@themathandphysicstutor yessirrr

[@mysteryplayer4723]

@@ying.jye_li5934 how much did u get bro

[@felixgong22]

Thank god I’m seeing this a day before the exam

[@themathandphysicstutor]

Better late than never

[@eth6521]

Thank you so much!

[@themathandphysicstutor]

You're welcome!

[@zbzb923]

Hey Sir, congratulations on getting more that 1k subscribers!!😆🎁🎊😁I am so happy for you.... Are you still planning to do the live session tho

[@ananyaanair917]

I think so - I read in another comment a while back that he may be having some issues getting started! I'm keeping my eyes open on his page reloading every few minutes!

[@themathandphysicstutor]

sorry for the delay!

[@zbzb923]

Math And Physics Tutor sir did u upload anything yet cause I didn’t receive any notification from you

[@zbzb923]

Ananyaa Nair hey did u attend the live session if u did can u send me what u got from the livestream unfortunately I didn’t attend it

[@ananyaanair917]

@@zbzb923 Hi there! I did watch it, but unfortunately, I couldn’t really take in-depth notes, because it was mostly a broad overview of things. Also, Mr. Finn made it clear afterward that he is only keeping it public until midnight EST (which has already passed) - I’m so sorry that you couldn’t attend :( But, just as a gist of what he stated: focus on connecting the dots (big ideas that encompass a lot of relationships) like conservation of energy and momentum; he also gave short review snippets of SHM, pulleys, etc. He recommends watching the playlists on these big ideas, especially ones you find difficult. Also, watch the solution videos he’s done recently and take note of whenever he says something is important. Rather than the answer itself, focus on how you get there and what key principles he used. Make a *very organized* (so you don’t waste precious time) sheet for every unit with these main ideas and have it with you for the test. As for any specific physics topic discussed (i.e. main ideas about SHM or Torque), you can just watch the topic videos in his channel and get those points! I think those were the key takeaways for me. I hope this helps you a bit! Good luck!

[@manningchen3300]

thank you for the amazing explanation. I just still have one small confusion. How do we know that the upwards direction is positive and that forces acting in the upwards direction do positive work and vice versa for downwards and negative? Is positive work being up and negative work being down just something thats arbitrarily defined?

[@themathandphysicstutor]

By the motion of the block

[@christian4478]

Is there any free response questions left to go over?

[@themathandphysicstutor]

not many

[@eugenetai1075]

I'm a bit confused about Part C in this question. The system is only the Block and the Earth so that means the Spring is doing outside work(Fs) on the block, changing Elastic Potential Energy to Kinetic Energy and applying it to the block. Wouldn't this change in Kinetic Energy increase the Total Mechanical Energy as the Spring is outside of the Earth-Block system?

[@Dan-gy2ts]

YOOOO. where are the new vids I gotta take the test AGAIN. I’m June. :(

[@themathandphysicstutor]

Haha. More videos to come

[@Dan-gy2ts]

Math And Physics Tutor can’t wait!!!! 🤣🤣🤣

[@MT-gc5xx]

thank you

[@themathandphysicstutor]

You're welcome

[@johnavonkim8653]

when you explained part b, you said that the force of the spring wouldn't change the ME. If that's the case, how would the Earth-Block system with no spring have decreasing ME?

[@themathandphysicstutor]

just because they defined it as the earth block does not mean the spring does act. That mean the earth block forces interactions are conserved.

[@ivanbatina9295]

Here 30 mins before exam

[@Multi777x]

In one of the college board videos, there was a problem where it asked to compare the total mechanical energy of two books that rotated around a ferris wheel. They defined the system as the book only and the ferris wheel was in uniform circular motion. Specifically, one of the books was rotating at the very bottom and another one close to the top. They stated the total mechanical energy of each book was the same as each other, but wouldn't that not be true since there is an external force (by Earth) so therefore energy is supposed to change?

[@themathandphysicstutor]

kzbin.info/www/bejne/opbFeYh7g9F0qbs

[@aden1683]

The net work done doesn't change. It is equal to F x d, the force of gravity never changes and it isn't acting parallel, i.e. the book is moving left and the force of gravity is downwards (same throughout the wheel).

[@kulahog6495]

Considering the fact that change in ME is determine by the relationship between the direction of the force, and of the motion; what if someone was ask to describe the change in ME on a block-earth system that is on a spring, and has an applied force pushing downwards, but is moving upwards, how would someone determine the change in ME, if there are multiple forces acting on opposite directions? Since it is moving upwards, do you prioritize the upwards direction of the spring causing the ME to increase, or the applied force which results in the ME decreasing?

[@carultch]

All that matters is what work the non-conservative forces are doing, in terms of identifying what happens to the total mechanical energy. If the net non-conservative work is positive, the total ME increases. If the net non-conservative work is negative, the total ME decreases. Usually, it is human forces that are the forces that do positive non-conservative work, while forces like kinetic friction and air drag do negative non-conservative work. Human forces can do negative work as well. Gravity, spring forces, electrostatics, and forces of constraint are all conservative forces. Anything with a potential energy associated with it, will be a conservative force. And work done by it, will be captured in the change in potential energy, which is within the domain of total mechanical energy.

[@黑羽快斗-y4n]

thanks bro

[@themathandphysicstutor]

No worries. Thanks for studing

[@dfflorida1694]

I can across this video researching whether cars oil system is closed. I have had a couple of reputable people tell me it is. Is it?

[@themathandphysicstutor]

No idea

[@samyang536]

are u still going live tn?

[@themathandphysicstutor]

I plan on it. Trying to learn how 🤯🤷🏻‍♂️

[@samyang536]

@@themathandphysicstutor great! You are a physics saviour

[@zbzb923]

Math And Physics Tutor thank you so much💖💖💖

[@yaadmanrizza]

I'm still a bit confused on something. In the question it said to calculate the change in mechanical energy when the spring was going back up from maximum displacement. If the system were just the block and spring and the they said the find the energy when the system was going back down from equilibrium, would the force of gravity do positive work since it would be directed in the motion of the block?

[@themathandphysicstutor]

Everything would change depending on the location of the block because the spring acts differently and the block accelerates differently at each point. But the analyzation would still be the same

[@dukebristow3216]

love these videos, why does ME increase when an object is in freefall if the system is defined as just the block.

[@nick2gateway581]

Because in free fall the only force acting on the block is gravity. That force acts in the same direction as the motion of the block, meaning its doing positive work. And since work is equal to the change in energy, ME increases.

[@themathandphysicstutor]

The force of gravity does work in the same direction of motion

[@carultch]

Total mechanical energy does not increase while an object is in free fall. The energy is traded between potential energy and kinetic energy, both of which are included in the domain of "total mechanical energy".

[@jonahkim7503]

Hello :). I just finished my AP Physics 1 test, and I just had some questions about it that I hope you could answer. I'll generalize it so it doesn't count as sharing the test. If the system is a cannon+cannonball, and cannon gets knocked back when firing due to conservation of momentum, but there is a frictional force on the cannon, would the mechanical energy be conserved or increase? i said increase, because the frictional force is an external force that moves in the direction of the center of mass. Is this wrong?

[@themathandphysicstutor]

I will discuss that test next week

[@InsanityLies0]

Thanks!!

[@themathandphysicstutor]

No problem!

[@samanthajester3312]

It’s over!!!!🥳🥳🥳

[@themathandphysicstutor]

How was it???

[@themathandphysicstutor]

Crap! You have to take it again?

[@ryanhartley8540]

Are you going to go over the test?

[@themathandphysicstutor]

Yes. As soon as the question are public they are released. I have made videos in 10 different. I think they will be allowed by college board to be release next week

[@ryanhartley8540]

Math And Physics Tutor awesome bro

[@Darkaction]

Could you upload the recent live please? :))

[@themathandphysicstutor]

Live until midnight

[@Darkaction]

Math And Physics Tutor Thank you 😁

[@dr.debruh2583]

Just a question. I thought for part b, it would stay constant because when the block and spring is fully stretched and at rest (L3) it has max spring potential energy only. As it travels to L2, the spring becomes less compressed while the block is gaining velocity, so spring potential energy decreases while kinetic energy increases. wouldn’t that mean that the energy of the block spring system is conserved? Can u explain what part of my thinking is wrong. Thank you!

[@themathandphysicstutor]

The part were you FORGOT ABOUT EARTH ACTING

[@dr.debruh2583]

Math And Physics Tutor But the system does not include earth, so we wouldn’t have to worry about gravity right?

[@InsanityLies0]

@@dr.debruh2583 You still need to worry about gravity. The system for part B consists of the spring and block but there is still the force of gravity acting on the block. The system does not include Earth, therefore the force of gravity is an external force. Since it's an external force and does negative work on the system, the total mechincal energy goes down.

[@lakshmansundaram7086]

Hi, I'm confused about one thing. If we have the open system of just the block, and Fs=Fg, would ME be conserved IF both forces were the same magnitude? (because there is no net acceleration)

[@themathandphysicstutor]

outside NET force make it open

[@Michael-ox6ex]

If all the outside forces cancel, can the mechanical energy be constant?

[@themathandphysicstutor]

Yes. An open system has an outside NET force acting

[@matthewsanchez4207]

Goat

[@themathandphysicstutor]

Love. Thank youi

[@swaggamuffin2171]

I have a question about the exams, in my class we use different variables for the formulas on the ap physics 1 equation sheet... do I have to use those variables or do the ap readers not care

[@themathandphysicstutor]

not sure what you mean.. but I would def use the variable that associated with each thing in the formula... like can you call Fnet.. "Z" and say Z=ma... NO!!!

[@swaggamuffin2171]

Math And Physics Tutor when I watch the review videos they will use mg instead of Fw (force of weight) or mgsintheta instead of Fa (force of acceleration) we used 2015 physics reference table...

[@thehobbyist146]

I really need help, does anyone know any good ap physics 1 study guides or review sheets, I'm self studying

[@themathandphysicstutor]

Right here bud!

[@ananyaanair917]

Hey! I'm self-studying too! This channel is awesome and also check out Flipping Physics and CB's live KZbin sessions if you haven't already. I found all of these to be super helpful in helping me think more conceptually in terms of physics rather than plugging in numbers into a formula, especially valid for this year's exam! Best of luck! You got this! :)

[@thehobbyist146]

@@ananyaanair917 dude I love Flipping Physics! Mr. P, Billy, Bobby, and Bo

[@ananyaanair917]

@@thehobbyist146 Sammee!! With Mr. Finn and Mr. P, I think we can rock this test! :) Best of luck!

[@danielfan8319]

does anyone know whether the questions were we have to design our experiments will be on the test?

[@matthewsanchez4207]

They are not

[@ananyaanair917]

Nope, the experimental design question is not on the exam! Just QQT and SA/PA! Good luck!

[@themathandphysicstutor]

go to the college board website and look at the question types. We have known this for weeks man! Comeon! 😥

[@seanbernhard4996]

Any updates?

[@themathandphysicstutor]

on what

[@seanbernhard4996]

Math And Physics Tutor the live stream, thank you so much for everything!

[@themathandphysicstutor]

oh. It was a great time!

[@ananyaanair917]

I was just watching the AP Timed Practice #2 Solution video on CB's KZbin AP Physics 1 playlist. The video is kzbin.info/www/bejne/eJmkdnqwpMt4eJI (the link is timestamped to take you to the part I'm talking about). For question 1 which is an adapted Ferris wheel question (you did a version of it from AP Classroom, but this is has some additional parts), in part (i) the correct answer was given was that for the book only system, ME is conserved. I thought that the book only system is a single object system, so Energy would change and gravity would do work on it. Why is isn't ME changing? If possible, I'd love to get your perspective. Thanks so much!!

[@themathandphysicstutor]

In my opinion, gravity would do external work on it and so would the Ferris wheels motor. Now if those two did equal and opposite work then the system would be closed and ME would remain constant. Remember from the video that an open system has an outside NET FORCE acting and ME is changed when that outside NET force does work. Without seeing the question, if they are stating that ME remained the same then gravity and and to motor did equal and opposite work on the system.

[@ananyaanair917]

@@themathandphysicstutor I did some digging on Mr. Jacobs's (CB KZbin teacher) twitter to see if he explained further. The repeated answer I see is that the question says that angular speed is constant (which means that linear speed is constant even though the directions of the components keep changing throughout). This means that KE is constant, so KE top = KE bottom. PE can't be included since Earth isn't in the system. And, thus ME is conserved? Even after reading it, I still find it confusing since it looks like an open system.

[@ananyaanair917]

twitter.com/JacobsPhysics/status/1258452966417346572 - link to the Twitter response

[@loveh6094]

What topics do you think will be on the AP Physics exam?

[@themathandphysicstutor]

1-7

[@jacobthigpen7281]

If the kinetic energy of the block is increasing, but the elastic potential energy of the spring is decreasing.

[@themathandphysicstutor]

is that question?

[@jacobthigpen7281]

@@themathandphysicstutor I understand it now!

[@AKD-le2kb]

W

[@themathandphysicstutor]

🤷🏻‍♂️

[@benberlowitz6381]

I thought a system had to be isolated not closed for energy to be conserved

[@themathandphysicstutor]

Not sure what you mean by isolated

[@carultch]

@@themathandphysicstutor The trio of terms, open system, closed system, and isolated system, are thermodynamics terms, referring to whether mass and/or energy can cross the system boundaries. An open system can have both mass and energy cross its boundaries. A closed system can have energy cross its boundaries, but not mass. An isolated system cannot have any mass or energy cross its boundaries. Whether forces of constraint could act on an isolated system or not, wouldn't be considered in the thermodynamics terms. It is a common misunderstanding to think that a closed system cannot have energy cross its boundaries, since that is what the term isolated system is intended to mean. All isolated systems are closed systems, but the converse is not necessarily true. You use the terms "open system" and "closed system" with similar, but somewhat different meanings to how they are used in thermodynamics. The way you use the word "closed system" is more like the concept of an isolated system in thermodynamics. Although it is more isolated than a thermodynamically isolated system, because your use of this term also excludes force and momentum interactions, that thermodynamics doesn't care about for zero-work forces.

[@Dan-gy2ts]

0/10 would not take the ap again

[@themathandphysicstutor]

Whoa!!

[@beyondlimits8159]

lol go to sleep man

[@themathandphysicstutor]

I can sleep next week!

[@bobthepotato4264]

Sleep is for normies