Good Problem Solving Habits For Freshmen Physics Majors

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  • เผยแพร่เมื่อ 28 ส.ค. 2024
  • If you're starting your first year in freshmen physics, this video could help put you on the right track to properly setting up problems. I solve a simple projectile motion problem, and show the importance of keeping equations in variable form, drawing diagrams, and other strategies that every physics major should make a habit of doing.

ความคิดเห็น • 685

  • @marcuskoseckshorts
    @marcuskoseckshorts 6 ปีที่แล้ว +3138

    Friend: How long did it take you to finish the physics homework?
    Me: 5 meters

  • @leyawonder2306
    @leyawonder2306 5 ปีที่แล้ว +1813

    "This is your first semester in physics
    The second semester is when you get into string theory"
    I'm dead😂😂😂

    • @theprinceofdarkness4679
      @theprinceofdarkness4679 5 ปีที่แล้ว +53

      That's an inside joke.

    • @aadarshabasnet1386
      @aadarshabasnet1386 5 ปีที่แล้ว +63

      I really liked how casually he says it. Very funny. Wasn’t expecting that. 😂😂😂

    • @CoryMck
      @CoryMck 5 ปีที่แล้ว +24

      I don't get how this is a joke, we learned string theory sophomore year of engineering at my school.
      Physics 2B: Optics, Special Relativity, and Quantum Mechanics.

    • @sayshusri2823
      @sayshusri2823 5 ปีที่แล้ว +9

      Thank god i thought it was only me..

    • @diamondshock4405
      @diamondshock4405 4 ปีที่แล้ว +12

      @@CoryMck That's first year at my uni. Of course, it's all relative to depth of the topic being covered in a particular class. A dedicated Quantum Mechanics class will go more in-depth than a class including it among other topics. So that's why people first touch Special Relativity & Quantum Mechanics at different times.

  • @JecIsBec
    @JecIsBec 5 ปีที่แล้ว +1463

    Andrew: "Whats going on, smart people"
    Me: "oh i guess im in the wrong place"

  • @StarboyXL9
    @StarboyXL9 5 ปีที่แล้ว +1362

    0/10 completely unrealistic. Not enough crying and questioning all of your life choices.

    • @siddharthnandi8567
      @siddharthnandi8567 4 ปีที่แล้ว +45

      Joel Gawne 11/10 would relate

    • @Smacy
      @Smacy 3 ปีที่แล้ว +14

      Why is this so accurate

    • @RecoveringReprobate
      @RecoveringReprobate 2 ปีที่แล้ว +2

      Fuck man.

    • @REALdavidmiscarriage
      @REALdavidmiscarriage ปีที่แล้ว +5

      i prefer to throw temper tantrums, smashing things and screaming around like a maniac…

    • @Morax___
      @Morax___ 9 หลายเดือนก่อน +1

      Really you people struggle with kinematics

  • @ComradePhoenix
    @ComradePhoenix 4 ปีที่แล้ว +188

    9:41 "You've gotta learn its ok to approximate things".
    Whatever the opposite of a vietnam flashback is, I had that for when my first semester prof cancelled out 3 and pi in an equation, and the entire class freaked the hell out. There was a math major in the row ahead of me, and he took it the worst. My reaction was something like "Ok, that's actually pretty cool".

    • @JITCompilation
      @JITCompilation 4 ปีที่แล้ว +26

      so its not just a meme!!! people actually do this

    • @ComradePhoenix
      @ComradePhoenix 4 ปีที่แล้ว +36

      @@JITCompilation the principle is sound as far as approximations go. Pi is about 5% greater than 3, and 3 is about 5% less than pi. As long as whatever you're doing can afford that error (it usually can), then it makes sense to do it.

    • @phaesiq8824
      @phaesiq8824 3 ปีที่แล้ว +21

      That is disgusting.

    • @msrikavya9651
      @msrikavya9651 3 ปีที่แล้ว +30

      So...that's how rockets fail?

    • @levilikesnothavinganycreat4971
      @levilikesnothavinganycreat4971 3 ปีที่แล้ว +1

      You can cancel pi and √g too, it makes stuff 1000x times easier

  • @froslassmismagius5859
    @froslassmismagius5859 6 ปีที่แล้ว +571

    It's okay to approximate things *TRIGGERED*

    • @legoblox01
      @legoblox01 5 ปีที่แล้ว +48

      @ki kus pi is the wonderful number that by itself is 3 but when squared it's 10

    • @Pedro-op6zj
      @Pedro-op6zj 5 ปีที่แล้ว +68

      Pi² = g

    • @shayanmoosavi9139
      @shayanmoosavi9139 5 ปีที่แล้ว +6

      @@Pedro-op6zj 😂😂😂😂😂

    • @southernkatrina8161
      @southernkatrina8161 4 ปีที่แล้ว +2

      G is 10m/sec □. Please!!!

    • @livethefuture2492
      @livethefuture2492 4 ปีที่แล้ว +7

      Fundamental Theorem of Engineering, π = e = 3

  • @TheCorbae
    @TheCorbae 6 ปีที่แล้ว +238

    I tutor for freshman physics and this is the method I use.
    A. Neatness and white space are your friends.
    1. Draw and label picture.
    1a. Free body diagram.
    2. Choose a zero point and axes.
    3. Make a list of your known quantities based on step 2.
    4. Check for SI units / unit consistency.
    5. Solve.
    6. Does your answer make sense?
    For some reason students are really against step 1. And definitely solve symbolically. Unfortunately the teacher at my school does not follow this practice. Mastering Physics is great for the instant feedback but it can lead to sloppy work. And it makes it too easy to google the answer. Step 6 is important. I had a student ask for help on a Mastering question. He'd entered a speed about a million times faster than light for the speed of a bullet. Another student calculated a surface charge density that was so ridiculously high that I responded, "Congratulations you just broke the universe."

    • @shaunakkulkarni4679
      @shaunakkulkarni4679 5 ปีที่แล้ว +6

      Oh got u. So what I like to do is name every variable Bob and guess what each number implies. I cram everything into one line and hope it works.

    • @TurdFurgeson571
      @TurdFurgeson571 4 ปีที่แล้ว +8

      How to solve physics problems in 6 easy steps, starting with A.

    • @mathlover2299
      @mathlover2299 2 ปีที่แล้ว

      @@TurdFurgeson571 That is not really a step. All of these are solid, this is how I always solve problems. When I was in university 10% of the credit for psets was to defend your answer. Taking limits is key to understanding your own solution.

    • @TurdFurgeson571
      @TurdFurgeson571 2 ปีที่แล้ว

      @@mathlover2299 Let me try again. List all of your favorite flavors starting with red.

    • @mathlover2299
      @mathlover2299 2 ปีที่แล้ว

      @@TurdFurgeson571 Let me try again. Being neat and economical with your paper is not a step it is a habit and a very good one at that.

  • @mpcc2022
    @mpcc2022 5 ปีที่แล้ว +341

    Andrew Dotson the Bob Ross of Physics.

    • @imashnake_7151
      @imashnake_7151 4 ปีที่แล้ว +26

      "Happy little cliff" I AM CRYING

  • @codenamerishi
    @codenamerishi 2 ปีที่แล้ว +128

    1) Draw Pretty Pictures - FUN PART
    2) Tool Box - RELAXING PART (just copy data)
    3) Relevant Equation - HARDEST PART
    4) Solving for things - BORING PART =(
    5) Sub in Data - SCARY PART (any stupid mistake here and final answer is wrong)

  • @marcioamaral7511
    @marcioamaral7511 6 ปีที่แล้ว +518

    A series of you deriving every classical mechanics eqs would be awesome

    • @QsHsNation1
      @QsHsNation1 6 ปีที่แล้ว +18

      F=ma can't be derived. It is a law. It was just thought about and written down.

    • @marcioamaral7511
      @marcioamaral7511 6 ปีที่แล้ว +49

      QsHsNation1 You seem to think that:
      1) Either I know just a little about physics so you can deceive me with such a poor comment
      2) You're a true troll of the web and if that's the case I can just ignore you
      3) You never read a decent classical mechanics textbook to see the equation F=dp/dt being linear momentum of a particle with mass m and velocity v
      => p=mv and therefore F=ma, being F©a (© stands for proporcional) if F acts in the same direction of the motion if you actually know how to take a simple derivative and the fact that mass is absolute in newtonian mechanics
      5) There's nothing in physics that isn't derived, and you should know that by now

    • @QsHsNation1
      @QsHsNation1 6 ปีที่แล้ว +58

      I'm not trolling? Look it up yourself, F=ma can not be derived, it is a law. The kinematic equations can be derived from the assumption of constant acceleration and knowing derivatives and simple Diff EQ's.

    • @marcioamaral7511
      @marcioamaral7511 6 ปีที่แล้ว +9

      QsHsNation1 You're blind enough to ignore the fact that I just derived it there?
      Another thing, we're not just talking about kinematics but also Dynamics and statics
      If you're going to keep insisting that F=ma can't be derived then I'm going to assume that you didn't learnt your physics right

    • @monku1521
      @monku1521 5 ปีที่แล้ว +43

      @@marcioamaral7511 F=ma is an axiom by the way.

  • @tempestandacomputer6951
    @tempestandacomputer6951 4 ปีที่แล้ว +115

    *Approximates gravity*
    Me: *an engineering freshman*
    "It's this where this stops applying to me?"

  • @speedspeed121
    @speedspeed121 6 ปีที่แล้ว +112

    You listened to me! Thanks!
    This was VERY helpful. I have been solving the first chapter problems in the text we will be using in Fall.
    "This is your first semester of physics. The second semester is when you get into String Theory."

  • @Thanatip2004BMZ
    @Thanatip2004BMZ 6 ปีที่แล้ว +284

    “First semester kinematics... second semester you do sting theory.”
    Umm... That seems like a HUUGGEEEE jump

  • @FalloutYakuza
    @FalloutYakuza 6 ปีที่แล้ว +256

    The only real thing that I find to be irritating about university physics is when your professor uses a different symbol for something then you do and you have to try to figure out what they are talking about. My university physics professor was European and he would use V0 instead of Vi for initial velocity and U instead of PE for potential energy. I also don't get why letters like P, W, and T are symbols for so many different things. Why don't they just have designated them with different symbols? It gets annoying when you have 2 different terms that are designated by the same symbol (e.g. T) and are in the same equation.

    • @eidechsebernstein954
      @eidechsebernstein954 6 ปีที่แล้ว +20

      I hate that both q and Q are used for charge

    • @Off_the_clock_astrophysicist
      @Off_the_clock_astrophysicist 6 ปีที่แล้ว +69

      Every aspiring physicist thinks they can come up with a universal notation, with symbols that are intuitive and used only for one thing. By the end of their undergraduate studies, after having read many textbooks, the aspiring physicist realizes that getting everyone to agree on one system is impossible. And then you go to graduate school, and a whole new world of Physics opens up. I had an intimidating but awesome Greek professor for my field theory course. After we had exhausted the roman alphabet and then the Greek alphabet, he joked that we should tap into the Cyrillic alphabet. Physicists can solve a lot of difficult problems, but notation seems to be one that's too hard to solve.
      Getting used to the notation is very important and not an insurmountable task. When I started out, I would make formula sheets, and also symbol sheets. Good textbooks will sometimes list the symbols they use. After a while, you get a feel for it, and you learn a few cues. "i" and "o" both mean "initial" and are both commonly used. Look at the broader context. If there is a rope involved, "T" means tension. If T appears together with a U and an E, then it's kinetic energy. If T is given in units of seconds, then it's a period. If you consistently use symbols while solving problems, they become second nature and it becomes easier and easier to identify what is what.

    • @charredmars2659
      @charredmars2659 6 ปีที่แล้ว +6

      This happened to me my senior year in AP Physics 2. My teacher taught us all these symbols and such and on the final he got from the local university he forgot to mention that some of the symbols were different. I saw the equations and recognized what each thing was, but he ended up writing all of the “translations” for the symbols on the board.

    • @satyampandey2222
      @satyampandey2222 5 ปีที่แล้ว +7

      I do not have problems with professors using different symbols.. you only need to understand what the equation means, you do not have to memorize it like your life depends on it

    • @satyampandey2222
      @satyampandey2222 5 ปีที่แล้ว +23

      Using V0 is actually better than Vi because V0 has subscript for t=0.

  • @SNoCappidona
    @SNoCappidona 5 ปีที่แล้ว +18

    One of the most important suggestions for me in early physics classes was to choose a coordinate system that make sense with the problem you're doing. you dont always have to choose positive y-axis to be up. physics works in any coordinate system, this will come in handy when you have many forces acting on an object at weird angles.

  • @FalloutYakuza
    @FalloutYakuza 6 ปีที่แล้ว +9

    My physics teacher in high school taught me to list all the terms that are given and "assumed" before starting a problem and it's incredibly helpful. Without listing everything that's given you would get lost really quickly and have to try to find all the given terms over and over again, which is time consuming. I also highly recommend drawing a diagram for every problem (especially kinematics, vector, and force problems) because it will help you visualize the question. University Physics 1 is mostly just high school physics, until you get into introductory orbital mechanics, buoyancy, and the Doppler effect, which is why I personally found University Physics 1 to be easy.

    • @oliviamehrer6844
      @oliviamehrer6844 2 ปีที่แล้ว

      Hi, can you explain what you mean by assumed?

  • @marcuskoseckshorts
    @marcuskoseckshorts 6 ปีที่แล้ว +36

    I'm so happy I'm not the only one that leaves it in variable form until the end! So much easier to keep track of everything!

    • @spencertaylor6910
      @spencertaylor6910 6 ปีที่แล้ว +8

      Marcus Koseck Yeah no one in my class does that besides me. But it's so much easier like that

    • @christopherjohnson2234
      @christopherjohnson2234 4 ปีที่แล้ว +1

      MAK_Ricco98 i do that in my math courses too and it drives my teachers insane for some reason

  • @autid
    @autid 6 ปีที่แล้ว +42

    I think you could do a whole video on dimensional analysis and sanity checking if you wanted.

  • @marcioamaral7511
    @marcioamaral7511 6 ปีที่แล้ว +132

    It's 1 AM in my country but I'm still watching physics because I love It

  • @bryamayvar6590
    @bryamayvar6590 5 ปีที่แล้ว +10

    You should talk about the why we solve for the thing we're looking for symbolically. I think its because it really allows us to appreciate the answer, because we can test the extremes and clearly see the relationship between the results, this is great though. I wish I would've seen it before my first semester. You should make another one!!!

    • @shayanmoosavi9139
      @shayanmoosavi9139 5 ปีที่แล้ว +1

      The reason is simple :
      To prevent mistakes in calculations. He already explained it.

  • @andyfang8762
    @andyfang8762 4 ปีที่แล้ว +10

    My highschool AP physics teacher taught us this method and he called it the standard model

  • @vukcevu5854
    @vukcevu5854 ปีที่แล้ว +3

    The second semester is when you get into string theory is still the best joke on TH-cam 😂😂😂😂

  • @enzonate9538
    @enzonate9538 4 ปีที่แล้ว +11

    I wish you were my physics C teacher. My teacher convolutes kinematics to the point where it seems like rocket science lmao

  • @sambrackett1975
    @sambrackett1975 ปีที่แล้ว +3

    Im an engineering major that kinda needs physics. My professor is on chapter like 6 now and I'm still at chapter -0. Not a number but Im exaggerating. I understand the newtons laws and all the material, but the math problems and how to start or where to get equations from is really what stumps me. This helped me kind of know where to start and im gonna continue watching your videos to see if it helps more, so thank you

  • @calebghirmai6478
    @calebghirmai6478 3 ปีที่แล้ว +2

    I never realized until now how helpful it is to solve for unknowns symbolically first. Thank you for this video. I will make sure to apply your recommendations.

  • @rai_l
    @rai_l 5 ปีที่แล้ว +4

    I'm a hs junior and my physics teacher always makes us use the toolbox approach for "show your work" problems

  • @CodyLlamos
    @CodyLlamos 4 ปีที่แล้ว +14

    Acceleration due to gravity on earth is always negative, your delta y in this case will be a negative 50 canceling the negatives

    • @samuelnell3737
      @samuelnell3737 4 ปีที่แล้ว +2

      Assuming you're taking up as positive

    • @rusejames7242
      @rusejames7242 4 ปีที่แล้ว +13

      It doesn't matter, define downwards to be positive direction

    • @JJSmalls
      @JJSmalls 3 ปีที่แล้ว

      I agree; it makes the problem easier to assume down is positive as a convenience.
      The video glossed over that part.

  • @Excidium96
    @Excidium96 6 ปีที่แล้ว +27

    very helpful video for us physics noobs!

  • @proof-xx1vv
    @proof-xx1vv 6 ปีที่แล้ว +27

    dude, please continue with your tensors series.

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  6 ปีที่แล้ว +7

      Next video is coming out either tomorrow or saturday for sure.

  • @victorserras
    @victorserras 6 ปีที่แล้ว +3

    I study statistics but I solve my problems basically the same way you do haha. I also prefer to write the steps I'm taking, most of the time. For example if I need to do some integral, i write "1st step: algebraic manipulation" to make the expression easier to handle, "2nd step: u-sub", "3rd step: integration by parts", 4th step undo substitution, 5th step now that I have the antiderivative, just plug in the integration limits.

  • @jamesdennis6120
    @jamesdennis6120 2 ปีที่แล้ว +3

    Literally in my third year and this is still useful. I have extreme ADHD and things don't flow in the same processes in my mind but this break down is like what my approach is bordering. I was never able to pin it down into an actual form so I can establish a single expedited process for solving problems. Even though this was directed at a first year, it definitely is going to help me and just gave me the urge to start working on some problems from this past semester.. although it literally just ended.
    The cool thing is that I struggle with values due to the ADHD (it gives me dyslexic tendencies) but I am amazing at symbolically working with problems. In my mind I equate the symbols to the actual phenomena I picture in my head. It's easier that way for me because I can then sometimes cheat when I don't fully know what formula to use. I would look at whats given, look at what I need to solve and understand the units associated with the end results. This way I can lean on the units to get me through a problem without really understanding which formula to use. It always leads me down cool approaches with correct solutions. I've gotten comments a couple times on my assignments and exams for unorthodox approaches hahaha. But, it's just because those cases I had leaned on units to solve the problem; While trying to picture what was actually going on physically.

  • @dylantuttle7181
    @dylantuttle7181 6 ปีที่แล้ว +47

    Hey Andrew! I just finished my first year of my astrophysics degree. I was wondering what your thoughts were on how well tests are as indicators for your proficiency in physics. I'm doing well in my degree, but I'm worried it's because I'm good at learning how to write tests and not because I'm learning the material in a more fundamental way. Does that make any sense? If you have any tips on how to move more towards the latter, I'd really appreciate it, because I don't want to get a bachelors and then realize I don't know how to do real physics as soon as I start doing research!

    • @user-mg6fb7ix1q
      @user-mg6fb7ix1q 5 ปีที่แล้ว +11

      This is such a great question, something I myself have been struggling with. The ability to succeed in research and not only on a test is being capable to manipulate the acquired knowledge to solve problems rather than following a bunch of previously seen steps, you should be able to see patterns that are not as obvious and be able to recognize such patterns without previously being exposed to them. The question is can you do that. Try solving problems that are not in your textbook, problems you haven't encountered before. That's as far as I've come tbh it's not an easy task

    • @koketsomashele9633
      @koketsomashele9633 5 ปีที่แล้ว

      Dylan Tuttle co-ask😭

    • @mathlover2299
      @mathlover2299 2 ปีที่แล้ว

      Don't worry about tests, grades, marks or anything. Worry about your genuine understanding of the material and be honest with yourself. I was not great at tests but was really good at making everything very general and working out the nitty gritty with my classmates. I was not the best but I have real understanding of what is going on.

  • @GojoSenpai25
    @GojoSenpai25 6 ปีที่แล้ว +29

    Actually you can assume y to be negative as the ball is falling downwards and that way you can g negative and no worry about signs ( it's always better to have - g)

    • @unknown360ful
      @unknown360ful 6 ปีที่แล้ว +3

      Yeah I was thinking about how if this was a Young and Freedman problem they'd have both delta y and g negative!

    • @ohdevil6544
      @ohdevil6544 5 ปีที่แล้ว +19

      What’s the point of bringing on the burden of labeling everything with negatives that end up canceling out?
      When the vertical motion is in one direction (down in this case), you do yourself a favor by taking that one direction as positive

    • @Bollibompa
      @Bollibompa 5 ปีที่แล้ว +4

      @ki kus
      No, he said "it's always better to have -g" which is very not true. A negative sign is even if you do not think so less intuitive and more cumbersome algebraically than a positive sign.

  • @divyabhashini
    @divyabhashini 6 หลายเดือนก่อน +1

    I used to write that information's given in problems when I was in grade 11.also of my science teacher used to do it..and now I'm in grade 12.my high school teachers doesn't teach the way like my grade 11 teacher did.they put all data straightly to equations.and I'm getting used to it by imagine the equation and data in mind without write cuz time is priceless in exam.but I got stuck by using wrong equations..now It's fine..day by day lesson's getting harder..btw ty for the video.

  • @laith6752
    @laith6752 10 หลายเดือนก่อน

    You have no idea how massively u helped me in this. I m currently in my first year of uni and i never took physics before even though i understood the idea of projectile motions i couldnt really solve problems alone because in physics understanding and applying the info are two different things. i kept on searching of videos of the thought processes i have to go through in order to solve questions and i watched many vids but none of them really explained how they know what to do. thank god your video landed on my home page and i instantly clicked and it really did its job. im now able to solve alone after being in pressure for many days not knowing what to do. Thank you Andrew!

  • @hbmm1
    @hbmm1 3 ปีที่แล้ว +1

    I’m an engineering major and I’m taking physics online due to covid and this video saved me! Thank you for explaining your thought process!

  • @gnarlsley
    @gnarlsley 5 ปีที่แล้ว +49

    Oh no you draw your A's like I draw my 2s this is going to be confusing

    • @thaliarep2088
      @thaliarep2088 5 ปีที่แล้ว +3

      Garrett Thompson Yep. It got me too!!!

    • @ambarrivera6049
      @ambarrivera6049 4 ปีที่แล้ว

      He's good at explaining but his writing confuses me.

    • @leviackerman3033
      @leviackerman3033 4 ปีที่แล้ว

      YESS samee!

    • @tgg3249
      @tgg3249 3 ปีที่แล้ว

      lmaoooo

  • @chander.261
    @chander.261 3 ปีที่แล้ว +5

    1:06 literally any physics problem in high school.

  • @kristenrew4693
    @kristenrew4693 4 หลายเดือนก่อน

    I had to pause and comment because something you said hit me like a sack of bricks. You mentioned that if you gave someone a stone axe and fire and expected them to make an iPhone. I'm at the end of the semester of college physics I and I've been absolutely pulling my hair out at the convoluted way they teach physics at my school. I've never been so flipping confused and frustrated in my life (I'm taking calc and it makes so much sense! So why doesn't physics, right?) I feel like everytime I go to do homework I have to "reinvent the wheel", teach myself the basics from scratch each and every single time. It'd take me sooo long. I've also said time and time again that surely there must be a more intuitive way to learn physics and practice. I just wanted to thank you for acknowledging those feelings. This vid has helped a lot. And explains a lot of the annoying shit my professor does (skipping steps and whatnot when working through problems) if only I'd seen this at the beginning of the semester I would have saved a lot of grinding and frustration. I have a good grade in the class though, so maybe it was worth it!

  • @bite-sizedphysics137
    @bite-sizedphysics137 หลายเดือนก่อน

    Great teaching as this is very logical. As a former physics teacher for senior high school (pre-university), the steps he discussed is exactly how I also taught my students the right thought process when analyzing a physics problem.

  • @100decade100
    @100decade100 4 ปีที่แล้ว +3

    7:27
    “We rewrite it cause we’re not lazy”
    Damn , hits me in my nay2 😂

  • @sudhendrakambhamettu1092
    @sudhendrakambhamettu1092 6 ปีที่แล้ว +4

    Thanks A LOT.. Andrew!.... Killed it today....i bought a Schaum's book...and honestly, the way the problems are structured and great!...Very helpful for students like us who are just starting out!.... Luv Ya!

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  6 ปีที่แล้ว +2

      Glad you think so!

    • @sudhendrakambhamettu1092
      @sudhendrakambhamettu1092 6 ปีที่แล้ว

      Andrew Dotson All thanks to u!... U suggested this book waaay back in ur videos rem?.... That's where I came to know about this and bought it recently!

  • @mowolabi27
    @mowolabi27 2 หลายเดือนก่อน +1

    This was a really good video for A level Physics in the UK 🇬🇧.

  • @linuxgaminginfullhd60fps10
    @linuxgaminginfullhd60fps10 5 ปีที่แล้ว

    On the way to the final answer try to group symbolic variables into dimensionless coefficients. This helps to develop physics intuition. There are only 4 dimensionless things you can construct from speed, acceleration, length and time: (a*t^2/h), (a*t/v), (v*t/h) and (v^2 / (a*h)). If you have some powers involved it is usually convenient to divide by a numerical coefficient equal to the product of factorials of the powers involved(so the first dimensionless quantity becomes ((a*t^2)/(2h))). Those dimensionless things are quite common and repetitive in physics, so you should recognize what they mean.

  • @cesarjom
    @cesarjom 2 ปีที่แล้ว

    I find that is helpful to set up a coordinated (reference) system (in a diagram of physical scenario) so when I write out the equations of motion, it makes more sense when assigning initial velocity and positions (in x and y components).
    So in the example problem given, with xy coordinate setup such that x_initial = 0 and y_initial = h (h=10m).
    Note: here acceleration in y direction, a_y = -g, since the vector of gravity is pointing downward along y-axis.
    Then
    y = - g/2 * t^2 + v_y_initial * t + y_initial
    y = -g/2 * t^2 + 0 + h, since initial velocity in y direction is zero
    y = -g/2 * t^2 + h
    Now when y = 0, the ball has impacted the ground. We can solve for time (t ) it takes for ball to reach y = 0 (the ground)...
    y = 0 = -g/2 * t^2 + h
    g/2 * t^2 = h
    t = sqrt(2h/g)

  • @tatjanagobold2810
    @tatjanagobold2810 6 ปีที่แล้ว +3

    Wow that was actually a lot of fun! I really hope you will make videos like these more often if you can :)

  • @josiper6662
    @josiper6662 5 ปีที่แล้ว +1

    Considering that S is a vector, and the ball is moving downwards, we can interpret downwards as positive, hence acceleration in this case is also positive.

  • @The_Platinum_Realist
    @The_Platinum_Realist ปีที่แล้ว

    Okay this guy is chill. He’s got this subject down to a science. Subscribed.

  • @SharkyShocker
    @SharkyShocker 3 ปีที่แล้ว

    Near the end of my first semester taking Physics and have only recently started solving symbolically before inputting values...
    THE MAN ISN'T LYING. IT'S SOOOOOOO MUCH EASIER!!!

  • @graceful522
    @graceful522 2 ปีที่แล้ว

    This is actually so useful. I did basically this problem on a test and was just guessing at what I should do, but it seems so easy when you do it...

  • @robbieroe9834
    @robbieroe9834 3 ปีที่แล้ว +1

    This video was super helpful. I’m learning grade 12 physics through a distance program, so pretty much without a teacher.

  • @lilnootle8648
    @lilnootle8648 4 ปีที่แล้ว +12

    I'm in the ninth grade idk why this popped up in my recommendationd. I fear no man but that thing scares me

    • @123ucr
      @123ucr 4 ปีที่แล้ว +2

      Lil Nootle- When I was in the ninth grade or about your age, I remember taking conceptual Physics. My 9th grade Physics class was a joke at my high school. Why? Because all I needed was mostly Algebra 1 and Pre-algebra (e.g. pythagorean theorem, scientific notation) skills in order to do well in the course. Not to mention, if you read the textbook and slides, do well on the homework, labs and study hard for the quizzes and exams, you will probably get an A in the course. Yes, I took it concurrently with my Honors Geometry class and the harder conceptual Physics problems required knowledge of geometry (e.g. vectors and circles) or basic trigonometry. But I remember getting an A (both semesters) in Conceptual Physics. This was the simplest high school science class for me. College physics on the other hand required knowledge of Algebra (basic to advanced), Geometry, Trigonometry and Single Variable Calculus (both differential and integral). College Physics was two to three times harder than Conceptual Physics.

    • @123ucr
      @123ucr 4 ปีที่แล้ว

      @Mikolaj Kraszewski Agreed. Math and Physics can be fun. Yes, they can be challenging especially if you take Upper Division Physics and advanced math classes such as Calculus 2 and 3, Linear Algebra, Intro to Differential Equations and beyond (e.g. Real Analysis, Abstract Algebra, Partial Differential Equations, etc.). Me, I passed Calculus 1 and 2 and a full year of General Physics but never got passed Calculus 3, Linear Algebra and Differential Equations and never took any upper-division Physics. Ironically, my favorite math classes were my toughest math classes in college (e.g. Calc 3, Linear Algebra and Differential Equations).

  • @enjoious
    @enjoious 5 ปีที่แล้ว +3

    I’m in my second semester as a mech engineering student and am so glad I learned dimensional analysis. It really helps with understanding symbolic form and solving variable equations. I start my first physics class in the fall, along with statics, so I’ll be a repeat viewer here for sure.

    • @kcwidman
      @kcwidman 5 ปีที่แล้ว +1

      Dimensional analysis? Like for unit conversions?

    • @enjoious
      @enjoious 5 ปีที่แล้ว +1

      Kai Widman Yes but also checking the consistency and plausibility of a formula’s units.

  • @user-cx3lo9lg2i
    @user-cx3lo9lg2i 7 หลายเดือนก่อน

    This man made my homework look easy, I actually understood whats going on

  • @ziggymcdougal
    @ziggymcdougal 5 ปีที่แล้ว +3

    It's really easy for me to forget signs so I usually like to draw directional arrows or cardinal directions to help orient vectors and whatnot. Especially when dealing with banked turn problems. (It really gets bad in aero mechanics lol).

  • @anthonym4205
    @anthonym4205 5 ปีที่แล้ว +4

    I have my physics final comin up soon. Thank you for this.

  • @andrewalmodovar1227
    @andrewalmodovar1227 2 ปีที่แล้ว

    I wish my teacher would’ve said to “keep things in symbolic form” that would’ve helped a TON

  • @HDitzzDH
    @HDitzzDH 4 ปีที่แล้ว +7

    9:38 Should have approximated it to π².

    • @mackenzies4666
      @mackenzies4666 4 ปีที่แล้ว

      Why?

    • @AthenianStranger
      @AthenianStranger 4 ปีที่แล้ว

      Mackenzie Sather because π^2 (π * π) is very close to the gravitational acceleration constant (3.14*3.14=9.8596). Using π^2 makes it easier to work with the square root. You’d have sqrt((10^2)/(π^2))==sqrt(10^2)/sqrt(π^2)==10/π.
      His answer of sqrt(10) is roughly 3.16s while 10/π is roughly 3.18s, meaning the ball was moving slightly more slowly than his estimate; however, both methods are fine for quick approximation. As a math teacher, I think the math is prettier with substituting π^2 for g.
      Here’s a great article about the relationship between π and g: www.wired.com/2013/03/what-does-pi-have-to-do-with-gravity/

  • @genzcat3500
    @genzcat3500 4 ปีที่แล้ว +3

    Andrew: Here is our "Happy little cliff here"
    My brain: Why shouldn't you jump off "Andrew's happy little cliff"?

  • @cameron3426
    @cameron3426 2 ปีที่แล้ว +2

    I'm a junior in highschool. I think I'm the only one in this comment section to not be in college

  • @DarkSkinKing9235
    @DarkSkinKing9235 2 ปีที่แล้ว

    this is such a big help thank you so much I'm in high school taking AP Physics 1 in 2 weeks and wanted to get a feel for it.

  • @zachkelly6188
    @zachkelly6188 6 ปีที่แล้ว +1

    I’m going into my first year of Engineering this fall. Thanks for the info. Great vid!

    • @sudhendrakambhamettu1092
      @sudhendrakambhamettu1092 6 ปีที่แล้ว

      Me too mate!..... which engineering major did u apply for?

    • @zachkelly6188
      @zachkelly6188 6 ปีที่แล้ว

      The program I'm taking is called the Fundamentals of Engineering Transfer Program. I don't have to declare till near the end of my first year, but right now I'm interested in mechanical engineering.

  • @bluedemonian
    @bluedemonian 5 ปีที่แล้ว +2

    You said "Gravity can only be positive". You wrote deltaY, which actually is negative, so gravity must be negative too according to your reference system.

  • @AgentJRock805
    @AgentJRock805 4 ปีที่แล้ว

    Im a geoscience major. Physics is down the road for me, but Im trying to see what Im getting into. Some of your other videos have scared me. I just have to remind myself, Im not a physics major (albeit I may do geophysics if I like it). This video was a great starting point for people entering physics. Honestly, this applies to a lot of the maths leading up to Physics. So awesome job. Keep these up

    • @chemicalnamesargon
      @chemicalnamesargon 6 วันที่ผ่านมา

      how are you finding it, assuming you've graduated now? I'm looking into majoring in chemistry and geoscience or physics (2 majors is what everyone does here.) would love any insights on studying geoscience :)

  • @gretanevergretel2550
    @gretanevergretel2550 4 ปีที่แล้ว +4

    You wrote 10 for gravity and my soul descended directly into purgatory, replaying that instant over and over again in my mind’s eye. “But it’s not precise enough” and “someone could die!” both ring in my mind, haunting me for eternity. But seriously, dude, as a mechanical engineering student, I thought the 9.8 was your approximation of 9.81 so when you approximated to 10, I stopped breathing a little.

  • @firefoxuser2557
    @firefoxuser2557 4 ปีที่แล้ว +1

    i've heard of negative time.... never imaginary time.. nice!

  • @spooked8007
    @spooked8007 5 ปีที่แล้ว

    You can also take it a step further and figure out the horizontal displacement value by multiplying the speed (10m/s) by the time (10.19s) and you get that the ball traveled 101.9 m before it hit the ground

  • @etengobasesamufala23
    @etengobasesamufala23 5 ปีที่แล้ว +2

    am very grateful for this beautiful advice, thanks...

  • @francisgiovannicarizon5752
    @francisgiovannicarizon5752 4 ปีที่แล้ว

    This is how I think regarding the signs of gravity. We know it tells us the direction(going down). In this case, if I will use a negative gravity(because I can lol), I will have to make the vertical distance a negative also because the ball was initially 50 meters above the ground and and it goes to 0 meters above the ground. From 50 to 0, it is decreasing so might as well treat it as negative.

  • @gristly_knuckle
    @gristly_knuckle 5 ปีที่แล้ว +1

    Oh I remember this one free body diagram problem. You had to see the machine and draw it from a new angle. I was not as good at this task.

  • @flalasap
    @flalasap 5 ปีที่แล้ว +50

    hes so hot and smart omg

  • @CODE7X
    @CODE7X 2 ปีที่แล้ว +1

    I had to use vpn for TH-cam to show me this masterpiece.

  • @InspirationofGenius
    @InspirationofGenius 6 ปีที่แล้ว +1

    Hi Andrew! I'm a second year physics undergrad currently working on a summer research project with my professor, investigating proposed convective parameterizations to improve cloud and weather climate models. Anyway, in my project I have to work with very large datasets in Python and figure out how to solve for many variables before applying them to the models, and plot comparative graphs in Python. This is my first time working with Python, so it's taking a bit of extra time becoming acquainted with it. I was wondering if you could make a video talking about how you learned Python or offer any tips on learning it more efficiently, and maybe recommend some good resources to help become more fluent with numpy, scipy, matplotlibpy, etc.. Thanks for making the awesome physics videos, I really enjoy them! :)

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  6 ปีที่แล้ว +2

      Hi! Sounds like an interesting project. Thanks for the nice comment! And yeah I could try to think of something along those lines

    • @andresgonzalez8904
      @andresgonzalez8904 5 ปีที่แล้ว

      No one gives a fuck mate

  • @Krishnarahul7
    @Krishnarahul7 5 ปีที่แล้ว +1

    Thank you very much sir i am from india i am struggling to solve jee physics problems but seeing this video it made very much easy

  • @binita4672
    @binita4672 2 ปีที่แล้ว

    Thanks for the book you suggested.. I'm having so much fun solving them, can't thank you enough:)

  • @christopherspencer2143
    @christopherspencer2143 3 ปีที่แล้ว

    I have a copy of Shaum's 3000 on it's way to my doorstep. Should be here in a few hours. Thanks for the recommendation!

  • @billymcgregor2067
    @billymcgregor2067 5 ปีที่แล้ว

    I always learned that the convention for g being negative makes more sense because a positive delta_s would represent a change in position upwards and a negative one would be a change in position downwards, it doesn't really matter in the end since it's just convention but it makes more sense that the convention would be intuitive like up is positive and down is negative.

  • @jonathanknight3704
    @jonathanknight3704 5 ปีที่แล้ว

    The g was positive because you chose downwards to be positive by writing delta(y) =50. If you chose it to be -50, g would also be negative and so would also her a positive answer for time.

  • @nukepizzaa
    @nukepizzaa 5 ปีที่แล้ว +2

    9:18 looping in my soul forever
    "Im..Yes..Cool."

  • @minmaxmarty
    @minmaxmarty 4 ปีที่แล้ว

    This was very helpful Andrew, thank you very much!

  • @kyrapeterson7207
    @kyrapeterson7207 5 ปีที่แล้ว +1

    Could you do a video on waves/frequency/sounds/ cynamatics?
    I notice when you face the board the frequency seems low and when you face the camera it's high frequency.
    Have you yet had to try and formulate and solve an equation for a school report? Do you have to do anything like that in freshman year?
    I apologize for all the questions, I have recently have got a passion for math and physics and I love it!!

  • @ethanolcott3960
    @ethanolcott3960 2 ปีที่แล้ว

    technically the gravity is negative but it cancels with the delta y because that should also be negative.

  • @wetpaperbag1346
    @wetpaperbag1346 5 ปีที่แล้ว +3

    I'm going to be honest, Andrew. If I saw your vids when I was in high school I probably would've chosen Physics as a major instead of Math. Doesn't really matter, though, because I ended up changing to Accounting anyways.

    • @sayshusri2823
      @sayshusri2823 5 ปีที่แล้ว +2

      Wow tht took a turn

    • @wetpaperbag1346
      @wetpaperbag1346 5 ปีที่แล้ว +1

      @@sayshusri2823 yeah, I'm not a good student so I chose Accounting. It's fun enough and offers excellent job security.

    • @shadyg1816
      @shadyg1816 4 ปีที่แล้ว

      Connor Reilly whats the money like? Im interested in this

  • @Think567
    @Think567 4 ปีที่แล้ว

    "Happy little cliff" nice.... I am not a physics major but I am enjoying your videos.

  • @antoniomendoza8590
    @antoniomendoza8590 5 ปีที่แล้ว

    Thank you so much I am starting physics this week can't wait!

  • @AreebKhan-wm7hc
    @AreebKhan-wm7hc 6 ปีที่แล้ว +2

    Really helpful man. I'm starting first year Mechanical engineering in september. Probably gonna be a pain in the ass but should be interesting

    • @marcioamaral7511
      @marcioamaral7511 6 ปีที่แล้ว +2

      wait until you take this same problem with air resistance

    • @AreebKhan-wm7hc
      @AreebKhan-wm7hc 6 ปีที่แล้ว

      Can't wait(!)

    • @FalloutYakuza
      @FalloutYakuza 6 ปีที่แล้ว

      At your school do engineering majors take university physics because at my school (Boston University) engineering majors take college physics instead.

    • @kamehamehaDdragon
      @kamehamehaDdragon 6 ปีที่แล้ว

      Caesarus Hyperius aren't college and university synonyms? XD

    • @FalloutYakuza
      @FalloutYakuza 6 ปีที่แล้ว

      DoobieDui College physics and university physics are differnet courses at my school. I went to Suffolk University for a year and college physics was basically an introduction to physics (level 111) whereas university physics was calculus based physics. Boston university has a difference except college physics (or general physics) is more geared towards engineers and university physics is more geared towards physicists. Both are calculus based and mostly the same course, however university physics goes deeper into physics and "more difficult"

  • @xeniyagvozdeva5119
    @xeniyagvozdeva5119 4 ปีที่แล้ว

    The real explanation of why the under-root number becomes positive is that delta y means the difference between the final and the initial height (in this case we have to write 0 - 50 ), so that -50/-9.8 will give us the positive number

  • @HackersSun
    @HackersSun 5 ปีที่แล้ว +3

    Well you taught me more how to do it than my professor.. He expected me to know this right off the bat
    I was taught to walk before I run
    He just just put on a jetpack and starting *flying*
    .. Ok

  • @hangkertzy9722
    @hangkertzy9722 4 ปีที่แล้ว +1

    You’re amazing at this!

  • @Naijiri.
    @Naijiri. 4 ปีที่แล้ว

    Im in high school (ap phys 1) and through regular physics and the beginning of this course I never solved for the variable first like you showed im going to start doing that thanks

  • @randyzeitman1354
    @randyzeitman1354 ปีที่แล้ว

    I kind of thinking that any person who gets to college and can study physics has already developed pretty good problem-solving skills.

  • @papi_chulo-
    @papi_chulo- 5 ปีที่แล้ว +1

    I took physics as a freshman in highschool bc my principal tought my class was good enough so make sure u pay attention bc if u dont ur screwed

  • @nathaliagracelee5116
    @nathaliagracelee5116 2 ปีที่แล้ว

    this enlightens me somehow, thanks for making this video💙

  • @danielsjohnson
    @danielsjohnson 4 ปีที่แล้ว

    10:37 This process could be used to solve problems in high school. The difference is the math is much simpler then. I'm going to use this method to teach kids. Thanks.

  • @theanimationlads7598
    @theanimationlads7598 4 ปีที่แล้ว

    Finally a video where I actually understand what he’s doing

  • @ayushgupta2453
    @ayushgupta2453 4 ปีที่แล้ว +2

    Meanwhile the IITian: ummm... Time of flight.... Root 2h /g... So root 10 secs.....

  • @johnnyc8669
    @johnnyc8669 5 ปีที่แล้ว

    Gravity constant should be negative. The negative cancels out because delta y is also negative because it's final y is 0 and initial is 50m. So delta y = -50m. The two negative cancels out. If you're teaching younger physics students, I don't think it's the best idea to tell them to merely choose if gravity is negative even though you still arrive at the correct answer.

  • @painlesspics
    @painlesspics 4 ปีที่แล้ว

    Wish I saw this video 3 years ago. Great explanation

  • @Yokie05
    @Yokie05 4 ปีที่แล้ว

    I'm not even a physics major ( Chemistry major) but i do have to take some physics classes, this video really helps.

  • @manskiptruck
    @manskiptruck 5 ปีที่แล้ว

    It's easy to know if it's negative or positive. If it's travelling in the direction of acceleration its positive. If it's travelling against the direction of acceleration its negative.