Rigid Bodies Conservation of Momentum Dynamics (Learn to solve any question)

[@sadadreza5745]

I got a 72% on my first mid in Dynamics. Then I happened to bump onto this playlist. Today I passed this class with a 91%. I don't think I can ever express enough gratitude to you. God bless you and I hope you enjoy a lot of success!

[@QuestionSolutions]

AWESOME!!!! I am so happy, you have no idea. Very well done. Makes me very glad to hear since that means these videos helped you out :) I wish you the very best in your future endeavors. Also, thank you for letting me know this, I appreciate it.

[@maxperlov7071]

I just wanted to say thank you so much. Best dynamics playlist on KZbin , you are the GOAT.

[@QuestionSolutions]

Thank you very much. I really appreciate your comment and I hope you do amazingly in your courses.

[@koengoedhart9849]

Thank you for making these video's, i justed watched the entire playlist, you'are a true hero!

[@QuestionSolutions]

You're very welcome! Thanks for watching all of them and I hope they helped you out.

[@dainross5321]

You are a gift! I wish I found this series earlier during my Dynamics class, but now I have it right before finals and it's helping a bunch. Thank you so much for the awesome animations and explanations!

[@QuestionSolutions]

Better late than never 😅 I wish you the best on your finals, you got this!

[@connorfitzgibbon9393]

Absolute kudos to you. Not only did you help me through a tough dynamics course, but you're still replying to comments and answering questions to you. If only you taught all my subjects...

[@QuestionSolutions]

Thank you very much for your comment, it was really nice :) I am super happy to hear that these videos helped you out, and hopefully one day, I will have more videos out about different subjects that might help you out more. Best wishes with your studies and keep up the good work!

[@siriwipakamma8982]

I never leave comments on youtube. This is my first comment on KZbin ever! I found your videos are really helpful. Today is the last day of my dynamics class. I finished watching your videos. They really helped me to solve the problems! I wish my professor could explain the class like this. Thank you so much for your hard work. I really enjoyed the dynamics with you!

[@QuestionSolutions]

Thank you so very much for taking the time to comment. I am really glad and happy all of these videos helped you. I wish you the absolute best in your future courses and other endeavors. Do your best 👍

[@scxrs139]

You have been a staple in my education and I would not have the grasp I do of Statics and Dynamics if without your channel. Thank you

[@QuestionSolutions]

You're very welcome. I am happy to hear these videos helped you out. Keep up the good work :)

[@hamanprnzhd6746]

This is my little way of appreciating you for the great things you have provided so far for this course and also other courses on this channel. You demystified the dynamics course for me and also made me understand the confusing concepts of my other second year Aerospace engineering courses in Ryerson University. keep up man...educational system needs more people like you with this level of knowledge

[@QuestionSolutions]

Thank you very much! I really appreciate your comment. Best of luck with your Aerospace engineering course. :)

[@dapz]

thanks for these videos, they were a huge help

[@QuestionSolutions]

You're very welcome and I am super happy to hear these were helpful to you. Keep up the good work and best wishes with your studies!

[@minmax3160]

ur short videos literally explains the concepts better than my 2hour lectures. Good job man, thanks a lot. Gonna go into my final with much more confidence now.

[@QuestionSolutions]

I try my best to make them as concise as possible. Glad to hear they are helpful :)Best wishes on your finals!

[@rehanrashid9296]

Thank you for the videos. Your videos help me excel in my 2nd year Mechanical Engineering Dynamics course, in a Toronto University!!

[@QuestionSolutions]

I am really glad to hear that! University of Toronto?

[@rehanrashid9296]

@@QuestionSolutions no, York University!

[@QuestionSolutions]

@@rehanrashid9296 👍 Best of luck with your studies!

[@eglaff492]

let's support his channel by not skipping the ads! we are indebted to you brother. thank you very much!

[@QuestionSolutions]

Thank you so very much :)

[@e-nes4042]

I watched all your dynamic videos (91 videos) thank you so much. Most of the questions you solved came out in the exam.

[@QuestionSolutions]

Wow, that's great! I am really happy and I hope you did splendidly on your exam :)

[@yasiruamarasinghe2285]

Thank you very much i have completed your entire dynamic playlist. Now i feel i can do something with engineering dynamics.

[@QuestionSolutions]

Awesome! I hope you do amazingly in your future endeavors :)

[@user-si1sh2lr8r]

i love you!!!!!!!!!!!!!!! thanks for the playlist.

[@QuestionSolutions]

You're very welcome!

[@ja6537]

Thank you very much for your statics and dynamic videos. They are really helpful and save me a lot of time. I was wondering if you also gonna make videos about 'mechanics of materials'. That would be wonderful! Keep up the good work!

[@QuestionSolutions]

You’re very welcome! I’m thrilled to hear that the videos on statics and dynamics have been helpful to you. It’s great to know that they are saving you time. Mechanics of materials is on my to-do list, I just don't know when I can get to it. On the bright side, there are lots of videos on KZbin about that topic so I hope those will be helpful to you. :)

[@ezequielolvera516]

You are doing God's work. Thank you so much for your great videos! They are very well done.

[@QuestionSolutions]

Thank you for your kind comment. I appreciate it. 👍

[@user-lw4bf6oy5u]

Thank you very much, u helped me doing well in the final exam❤️❤️❤️❤️❤️

[@QuestionSolutions]

That's awesome to hear! ❤

[@pradaneo9028]

Thank you for these, I got my final in 6 hours

[@QuestionSolutions]

Do your best and I wish you all the success in your final!

[@TheSpokenBanana]

Finished my review of the dynamics playlist! I have my dynamics final on Tuesday which I'm very worried for, but you've explained these concepts a lot better than my professor has so I feel a bit better. I definitely feel a lot more confident on these concepts than I did before but there is still a good amount of doubt in me. Wish me luck! I hope I return with good news.

[@QuestionSolutions]

I hope you do really well on your final exam. If you have the time, doing as many questions as you can is the best method of getting comfortable and building up confidence. You got this! Let me know how it goes :)

[@TheSpokenBanana]

@@QuestionSolutions I come back with good news! I did indeed pass! I can't see what I got in the final, but my first two midterms were pretty bad to say the least and I needed a 60 on the final for a C-, but I ended up with a B in the class! Thank you so much again for you videos, they helped me immensely.

[@QuestionSolutions]

@@TheSpokenBanana That's very good news! I am really happy for you and glad to hear these videos helped :) Keep up the great work!

[@epik_robie1709]

At 2:16 the equation IgaWa=IgbWb doesn't seem to be in your other videos, do you have a resource that explains that equation in more depth? I am unfamiliar with it.

[@QuestionSolutions]

It's actually just the normal equation that's been used in many videos but a slightly different application of it. So you probably know angular momentum is equal to (H = Iω), I show this equation at 0:43. All we are saying is that the initial angular momentum is equal to the final angular momentum. This is really just extending what we did in the previous video with impulse and momentum but now we are saying this angular momentum is conserved.

[@evanlabyak174]

I have one question, for a uniformly massed bar that is fixed at the non-middle of the bar (ie say length L, fixed at L/3), would you still be able to use the center of gyration? Or would you have to use parallel axis theorem and add (1/3)mL^2?

[@QuestionSolutions]

You'd have to use the parallel axis theorem or find the equation on the internet. Sometimes, they give you the equations for certain locations or even different objects.

[@CengizSerkan]

do you think publishing these videos rests? ı finished all of the topics and ı appreciate your accurate and inferable presentation. thanks for all the your efforts.

[@QuestionSolutions]

I plan to continue whenever I get free time. Thank you for your kind comment. :)

[@user-ui6vz3zv8r]

Question, I'm planning to take dynamics next semester, so does this playset covers all the material and is dynamic an easy course comparing to thermodynamics for example. THANK YOU SOO MUCH YOU SAVED ME IN MY THERMO MIDTERM AND STATICS

[@QuestionSolutions]

I don't know what your course covers so I can't say for sure, but the dynamics playlist covers a lot of the normal topics talked about in a dynamics course.

[@padamyonjan5608]

Thank you for the video. I hope I pass the course with good grades. Are thermo fluid courses coming soon?

[@QuestionSolutions]

I hope you do amazingly on your courses. I won't be making thermo fluid videos, at least for the foreseeable future.

[@TheBlindFlame2]

Legend.

[@QuestionSolutions]

You are the legend for taking the time to comment! 👍

[@pure_ligma2387]

@@QuestionSolutions You are the legend for taking the time to comment you are the legend for taking the time to comment!

[@aashishkumarjha3993]

Can you tip me when to use 1. work energy principle or 2. total energy principle or 3.impulse principle to solve a physics problem?

[@QuestionSolutions]

Unfortunately, there isn't really a tip I can give you. It all depends on what is given to you in a problem. You will find that most questions can be solved using any of those methods, the question is, what will give me the quickest answer? That usually just comes from experience and doing a lot of questions, and really, what are the givens in a question.

[@Diggydogdraddy]

Sir, the videos you make are great, ill always be there to remind u. I got a question tho, for the first question, why didnt we take the mass moment of inertia of a rod rotating about a point (since his hands are pivited ), instead of just a normal thin rod?

[@QuestionSolutions]

So we actually found the mass moment of inertia bout the center of mass. That way, we can "compare" or use the same location for the second position, when he's tucked. We are saying the conservation of momentum about the center of mass when the gymnast is stretched is equal to the momentum when the gymnast is in a tucked position. Both at the center of mass. I hope that clears it up :)

[@Diggydogdraddy]

@@QuestionSolutions So the conservation of momentum basically only applies to the same point (same point in body at the initial location compared to that same point in the final location/state)?

[@QuestionSolutions]

@@Diggydogdraddy Yes, we usually compare the center of mass, but other points work as well, but the initial and final points have to be the same.

[@Diggydogdraddy]

@@QuestionSolutions Thank you so muchhhh, also i am curius if you dont mind me asking , how old are you? because You teach like you've had 15 years of experience haha

[@Diggydogdraddy]

@@QuestionSolutions Thank you so much kind sir.

[@Human-881]

When are you uploading chapter 20 (3D kinematics of a rigid body)?

[@QuestionSolutions]

Probably not for a long time. Currently, when I have time, I want to finish more thermodynamic videos.

[@silverbackdungeongorilla4315]

hey dude o'connor do you have videos about vibrations?

[@QuestionSolutions]

No, I don't.

[@nikioreskovic331]

Hi, I am a instructor in this field and i really like style of your videos. I am thinking of implemetnig some of this new animations in my classes, so i was wondering what software do you use?

[@QuestionSolutions]

Hi, that's great to hear! I use illustrator for the drawings and after effects for the animations.

[@nikioreskovic331]

@@QuestionSolutions Thank you

[@KontKledula]

In that question 2:32 don't should we get I as 1/3 * m * L^2. ? Because if we take it according to the center of gravity (1/12 * m * L^2), wouldn't we have to add the speed of point G? Thanks for tutorial btw.

[@QuestionSolutions]

As long as the points you compare are the same, it will yield the proper answer. So here, we write both equations about point G, with the only difference being slender rod vs circular disk.

[@darrylcarter3691]

For A On the first example, why don’t we use Angular momentum = (moment of Inertia x angular velocity) + (radius x mass x velocity)?

[@QuestionSolutions]

We actually don't need to since we are only comparing angular velocity. On a side note, we aren't given a linear velocity anyways 👍

[@jeffreydahmer2110]

that second question might be the most complicated ive come across lol

[@QuestionSolutions]

Gotta do a few complicated ones too :)

[@ersinortagenc1367]

In the first question, why we didnt calculate the "I" for the first position respect to gymnast's hand since it turns around his hand?

[@QuestionSolutions]

Everything was calculated about the center of mass, so there was no need to calculate I with respect to the hand.

[@ersinortagenc1367]

@@QuestionSolutions yes that's true but why we did that, I mean the man rotates around his hand so shouldn't the formula for I for the first state be this "(1/3)ml^2"

[@QuestionSolutions]

@@ersinortagenc1367 No, where he rotates doesn't matter for this problem because you're comparing the initial state at the center of mass to the final state at the center of mass. So really, all that matters is comparing the same 2 spots. If you wanted to, you can compare where he rotates, but then it becomes incredibly difficult since we would need to compare the same point at the 2nd state. Also, with these problems, you have to keep your eye out. Notice how in the diagram, they give a big black dot for the center of mass, that usually means we have to focus on that point. Let me know if that clears it up :)

[@germenfer]

Hello sir. Why is there no need to add the linear momentum of the gymnast's center of mass (I thought it would be H_A + L_A = H_B + L_B).

[@QuestionSolutions]

Here, we only need to consider angular momentum. However, tell me the linear momentum? Please write it out for me, like the equation with both angular and linear momentum. I would like to see your thought process :)

[@germenfer]

​@@QuestionSolutions Oh I think I understand now. I was thinking about ω_A*(1.75/2)*m+I_{G1}*ω_A=I_{G2}*ω_B.

[@QuestionSolutions]

@@germenfer I see, you were going to find the linear velocity. So yeah, for this problem, all you need to worry about the angular momentum. 👍

[@germenfer]

@@QuestionSolutions Great! Thanks a lot for your videos and for taking the time to answer me. I wish I had found this channel earlier, as it has been a blessing!

[@QuestionSolutions]

@@germenfer You're very welcome. I am really glad to hear the videos are helpful :) Best wishes with your studies.

[@darrylcarter3691]

I’ve notice that the question in the second example doesn’t look completed. You ended it with and. What comes after that?

[@QuestionSolutions]

Apologies, I didn't notice that :( It should say "and then rolls over it without slipping"

[@td1751]

Why is the gymnast example not calculated using the fixed axis rotation? You only use the momentum about the center of mass but we're analysing the angular velocity around the bar? Wouldn't we need to add mvr terms?

[@QuestionSolutions]

I am not sure if I understand your question. We don't need to use mvr terms because everything was calculated about the center of mass. Assume we did use mvr, we don't have enough givens to use it, i.e. we don't know the extension of the arms. Generally speaking, if the question gives you the center of mass, and which types of objects to use for the mass moment of inertia, then you can just rely on those to solve the problem. Also, we aren't analyzing the angular velocity around the bar, but of the center of mass of the gymnast since that's what the question wants.

[@td1751]

@@QuestionSolutions Hi, thanks for responding. I think I was confused with the angular velocity being denoted around the bar. I re-read the question and saw that that value is when he lets go of the bar.

[@bharatbsaxena561]

❤

[@QuestionSolutions]

❤

[@aburiyadh7788]

Last chapter in ME201 final exam , KFUPM students send their regards 🥰🥰🥰 .

[@QuestionSolutions]

I hope your exam went great! Best wishes with your future endeavors. :)

[@mnaliwien]

Why don't you use Ha=Ia.W + mvr? I'm confused about it.

[@QuestionSolutions]

Where are you referring to? Please provide timestamps so I know where to look.

[@mnaliwien]

@@QuestionSolutions 2:14 Thanks for your reply.

[@QuestionSolutions]

@@mnaliwien Please see this video first: kzbin.info/www/bejne/oaKweX6VqM57jqM especially the intro. We only use the extended form if we need to figure out the angular momentum that's not about the center of mass.

[@mnaliwien]

@@QuestionSolutions Thank you

[@QuestionSolutions]

@@mnaliwien You're welcome!

[@particleonazock2246]

Nice ads

[@QuestionSolutions]

I don't pick them 😅