Good Problem Solving Habits For Freshmen Physics Majors
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- Опубліковано 5 чер 2018
- 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.
Friend: How long did it take you to finish the physics homework?
Me: 5 meters
Wow that was so quick!!!!! It always takes me like 11 Wb so annoying
3 parsecs
LONG
r/woooosh
3 N/m... why anything wrong😉😉
Andrew: "Whats going on, smart people"
Me: "oh i guess im in the wrong place"
Awww, you're smart if you're interested in learning!
@@NovaWarrior77 you are kind and smart
@@executorarktanis2323 Thank you!!!
Think highly of yourself bro
Me: sooo this is what smart people do.
"This is your first semester in physics
The second semester is when you get into string theory"
I'm dead😂😂😂
That's an inside joke.
I really liked how casually he says it. Very funny. Wasn’t expecting that. 😂😂😂
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.
Thank god i thought it was only me..
@@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.
0/10 completely unrealistic. Not enough crying and questioning all of your life choices.
Joel Gawne 11/10 would relate
Why is this so accurate
Fuck man.
i prefer to throw temper tantrums, smashing things and screaming around like a maniac…
Really you people struggle with kinematics
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".
so its not just a meme!!! people actually do this
@@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.
That is disgusting.
So...that's how rockets fail?
You can cancel pi and √g too, it makes stuff 1000x times easier
Andrew Dotson the Bob Ross of Physics.
"Happy little cliff" I AM CRYING
It's okay to approximate things *TRIGGERED*
@ki kus pi is the wonderful number that by itself is 3 but when squared it's 10
Pi² = g
@@Pedro-op6zj 😂😂😂😂😂
G is 10m/sec □. Please!!!
Fundamental Theorem of Engineering, π = e = 3
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)
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."
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.
How to solve physics problems in 6 easy steps, starting with A.
@@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.
@@mathlover2299 Let me try again. List all of your favorite flavors starting with red.
@@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.
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."
*Approximates gravity*
Me: *an engineering freshman*
"It's this where this stops applying to me?"
Shut π=3
Its just a joke
A series of you deriving every classical mechanics eqs would be awesome
F=ma can't be derived. It is a law. It was just thought about and written down.
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
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.
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
@@marcioamaral7511 F=ma is an axiom by the way.
“First semester kinematics... second semester you do sting theory.”
Umm... That seems like a HUUGGEEEE jump
not really
It’s a joke
That's the joke
Are you familiar with my dear friend satire?
jump discontinuity
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.
I hate that both q and Q are used for charge
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.
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.
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
Using V0 is actually better than Vi because V0 has subscript for t=0.
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.
The second semester is when you get into string theory is still the best joke on UA-cam 😂😂😂😂
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.
Wow that was actually a lot of fun! I really hope you will make videos like these more often if you can :)
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!
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.
I think you could do a whole video on dimensional analysis and sanity checking if you wanted.
Not a bad idea.
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!
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.
Hi, can you explain what you mean by assumed?
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...
This was very helpful Andrew, thank you very much!
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
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!!!
The reason is simple :
To prevent mistakes in calculations. He already explained it.
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
Okay this guy is chill. He’s got this subject down to a science. Subscribed.
am very grateful for this beautiful advice, thanks...
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)
This video was super helpful. I’m learning grade 12 physics through a distance program, so pretty much without a teacher.
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.
Thank you so much I am starting physics this week can't wait!
Thanks for the book you suggested.. I'm having so much fun solving them, can't thank you enough:)
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!
Marcus Koseck Yeah no one in my class does that besides me. But it's so much easier like that
MAK_Ricco98 i do that in my math courses too and it drives my teachers insane for some reason
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.
My highschool AP physics teacher taught us this method and he called it the standard model
I wish you were my physics C teacher. My teacher convolutes kinematics to the point where it seems like rocket science lmao
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.
I have my physics final comin up soon. Thank you for this.
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).
This was so helpful, thank you for the videos
Thanks for the video. It was a really good one 👍
You’re amazing at this!
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.
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
this enlightens me somehow, thanks for making this video💙
I'm a hs junior and my physics teacher always makes us use the toolbox approach for "show your work" problems
Thx dude. Relearning this processes.
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
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.
I’m going into my first year of Engineering this fall. Thanks for the info. Great vid!
Me too mate!..... which engineering major did u apply for?
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.
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!!
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
Dude, thank you so much!
13:40 That's interesting. The only place where I've seen numbers since the beginning of my major is during experiments and mathematics courses. Even for the very first physics course in the very first quarter, which was on differential equations and stability, we had to do everything symbolically.
very helpful video for us physics noobs!
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!
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.
Thanks this helped with my highschool AP physics sumer homework.
thanks, clarified a few key points for me.
"Happy little cliff" nice.... I am not a physics major but I am enjoying your videos.
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!!!
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!
dude, please continue with your tensors series.
Next video is coming out either tomorrow or saturday for sure.
This was a really good video for A level Physics in the UK 🇬🇧.
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!
Glad you think so!
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!
Wish I saw this video 3 years ago. Great explanation
I love your videos. I loved physics in high school, and I plan to major in physics in the fall. Any advice?
This man made my homework look easy, I actually understood whats going on
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.
thanks dude I am getting better at using energy to solve projectiles, yay for ap physics I guess.
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.
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.
Wonderfully clear 👍👍👍
It's 1 AM in my country but I'm still watching physics because I love It
definately an INTP.
such a Brazilian...
1:19 here
This is the method my intro mechanics professor used except he had a few extra steps about choosing and origin and labeling our axes. He also solved everything with symbols and always included units, but my intro electricity and magnetism prof this semester never puts units on anything until the end and I keep losing what units go with what for the new electric constants we’re using lol
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.
I'm not even a physics major ( Chemistry major) but i do have to take some physics classes, this video really helps.
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.
Very Very helpful ! I was lost before watching this video
Acceleration due to gravity on earth is always negative, your delta y in this case will be a negative 50 canceling the negatives
Assuming you're taking up as positive
It doesn't matter, define downwards to be positive direction
I agree; it makes the problem easier to assume down is positive as a convenience.
The video glossed over that part.
Finally a video where I actually understand what he’s doing
Are there any other suggestions you have for solving problems in general? I just had my first physics exam, and it was bad. I am taking a physics course that is for biology majors. The problem weren't anything like the homework assignments I had. So, I need to change my approach when preparing for the exam to be able to do any problem and not just the hw problems. I don't have mastering physics, but I have something similar from another company, and it is useless. I've used mastering chemistry and it was the same thing. I want to become adept that I can do any physics problem and not flinch. I'm coming from a non-science background and have never had physics in my life. So any suggestions would be greatly welcomed.
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
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!
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
Dylan Tuttle co-ask😭
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.
What do you (or anyone else in the comments) do when you have to go through multiple long equations to get the answer? Like you have the equation you need but there are variables in that equation that you need to solve for separately with other (long) equations? It doesn’t make sense to substitute a ton of long equations together but my calc homework looks like a mess so any advice is welcome!
Thanks this is very useful
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.
More of this if possible plz.
technically the gravity is negative but it cancels with the delta y because that should also be negative.
i've heard of negative time.... never imaginary time.. nice!
Do you have any resources in addition to schaums for going over problems such as SHM, standing waves and fluid dynamics? My instructor is.... special to put it kindly and I want to spend the summer actually learning physics. Thanks.
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! :)
Hi! Sounds like an interesting project. Thanks for the nice comment! And yeah I could try to think of something along those lines
No one gives a fuck mate
1:06 literally any physics problem in high school.
Also, do operations in an order that takes least operations to do.
Thanks, bro…❤️
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)
Yeah I was thinking about how if this was a Young and Freedman problem they'd have both delta y and g negative!
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
@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.
I wish my teacher would’ve said to “keep things in symbolic form” that would’ve helped a TON