Work and Energy
ฝัง
- เผยแพร่เมื่อ 5 มี.ค. 2017
- What's work? Not that place you go to earn money. In physics it means something else. And what's energy? Not like in the groovy sense. Actually, energy is one of the most improperly used words in the English language. Let physics define these words for you!
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intro: professor so kiddish
video: very serious
We are trying to learn and you here doing memes😂
truth
riggght ....but also he looks so jewish too
Maot kaayo
@@ezzo3788 😂😂😂😂
Thank you soooooo much for making these videos. I know you have helped tons of students understanding the subjects more.
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"Colloquial connotations." Love it. It's a polite way of saying, "Don't embarrass yourself."
thanks dad
Ur welcome
@@DudeWhoSaysDeez no your patrick
What is he u r dad 😀😀That seems to be weird
@@devendrareddy816 hes ur dad as well.
He is Jesus
This man just summed up 3 hours of me reading the textbook in about 5 minutes... Truly good stuff and easy to understand. Thank you Hendy
These videos really help bring the concepts home! I am thoroughly impressed by your ability to explain these concepts in ways that just make sense to me. Thank you so much! This really makes the book and lecture material much more clear! Thank you!!!
You know you never really use too many examples or if you do they are simple, but honestly that should be the way they initial teach. It really helps me understand where things come from before practicing the actual examples later.
The introduction of cosine and its values influencing the amount of work really blew my mind for some reason. Being able to quantify things like that really makes me appreciate this crazy universe. These videos are immensely valuable and you are one of the reasons I have chosen to pursue an education in physics
Thank you so much Sir!!! I learn a lot from you!!! You're a blessing to students just like me who can't easily catch up with what their professors where teaching! Again, Thank you so much!! ❤
You’re awesome, was watching your videos to study, but actually found myself enjoying them. I love how you don’t skip over important details
This is so helpful it covered all that I needed for my quarter exam
Okay. So here is a very fundamental doubt.
We know that work = energy. (It definitely is. Because,
work=fd= 1/2mv(v)= energy
And energy is the ability to do work..(1)
That implies
Work=ability to do work (using (1))?😮😮
How can two things which are exactly equal can be different from each other?
Dear Dave: my appreciation for this excellent , simple and interesting explanation
legit the most helpful channel ive ever encountered for my physics class
This is so perfect. I needed something that teaches me how to do problems but in a very easy and fun way.
Thank you Mr. Dave, this is such a great summary; simply packed (?) and brief. I would like to share this on physics class.
Please do continue doing this sort of video, you really did help me with many of my assignments at school, I often come back watching your videos if I need help on what kind of phrasing should I use to be more understandable.
Also, the jokes. It's great.
I am learning a lot from you Professor Dave! Thank you so much po!
My man getting me right! We all appreciate your hard work.
Thank you smmmm!!! You're honestly physics Jesus who's going to help me more than my physics teacher ever will for HSC
Thanks for your video, you explain it very well and in a short amount of time
Hello, This guy actually teaches you more in 5 minutes than your teacher in an entire semester.
thank u dave 🤘 my advisor makes me watch these videos and as much as i hate working i learn a lot in these videos
Thanks for this video, Professor. A blessed day, everyone!
Thank you very much professor Dave, I had a lot of doubts but after watching this. It all makes sense now, thanks again!
I felt bamboozled knowing that this is the first video that I’ve seen that did not include comprehension in the end. But nonetheless you’re explanation are always superb thank you very much!
thanks very much for the explanations i am having a test tomorrow about work and energy and i feel much clever after i watched this video and i like the way you explain work and energy i cant wait to see more of your videos about KE and PE thanks for the video now even my sister carly can understand
5 years too late - but I hope the test went well for you.
Once again dude thank you
I've never understood these problems without you, thank you very very much bro. You're my professor. ❤ love frome 🇹🇭 🇹🇭 🇹🇭 🇹🇭.
Thank you so much ! Really appreciate it ❤
im so happy i found a youtuber that can help me with bioligy,chemistry and physicis this means so much to me.. u have no idea how ur helping me with my finals :)
Thanks very much pro
I attend your videos always and I got more knowledge from your teaching.
after watching his video for 3 times with the video from CrashCourse 2 times now i understand it with a smile face. We love you Pro Dave
Professor Dave is awesome, thank you so much
Matt Z Ditto. Great way to understand what energy is.
Thank you Professor Dave 👍👍👍
Clearly explained. Thank you
I didn't know Dave Grohl knew so much about Physics!
A lot of love to you Mr Dave from India
muchas gracias tú excelente!
(ขอบคุณหลายๆเด้อ)
You are my best teachers sir
This really helped me prepare for my test.
Thankful professor ❤💜
thank you professor
Excellent explanation.
you are such a great teacher, thanks for your effort
Any comments pls th-cam.com/video/Vw8U2dW03eY/w-d-xo.html
Thank you so much sir you are helping us a lot thank you so much ❤
Thank you so much 🎉
thanks. this is really nice.
AP exam this Friday thank you professor Dave 👍👍👍👍
Thanks sir ❤️
I love your tutorial sir
thank you. God bless
Hi, i am a student in grade six. Can you please explain what theta, cos and work-energy theorm? Thank you 🙏🏻
check out my mathematics playlist! or more specifically my trigonometry playlist.
Theeta is a greek letter, just like we use 'x' and 'y' to mark angles. Cos theeta means the effect of that force in the horizontal direction. For example if you hit a football in north-east direction, actually it had travelled in two perpendicular directions, north and east...the force which contributed for the force only to travel to east means Fcos(theeta)..its something like that..... And work energy theorem means that, the more energy u have, the more u can transfer it and do work...just like if u have more money, you can spend to buy more things and vice versa.. in physics, that spending to buy part should be replaced by 'making an object move'(do work)
clearly explained!
Am starting to love his ways😭❤️ specifically the introduction 🙌🤣🤣
Thank you !
You just got a new sub
Thankyou sir!
Thank you 👍👍👍
Thanks to animating that help me to understand lot
Belated Happy Teachers Daaaaaaaaaaaayy~!
Can you make a vedio about the machines in physics
Very good Professor Dave
it is really big help to me. thank you
Baby brother is pushing you with 1newton force and final work is 6N.m
my teachers' so lazy that she just tells us to search the lessons at home : /////
WutFace
That’s a terrible teacher our teacher gives us a book and notebooks and tells us its do tomorrow
Uhhhh same 😑😞
she was prepping you for the apocalypse
Lmao basically online class
In physics, "work" is when a force applied to an object moves the object in the same direction as the force. If someone pushes against a wall, no work is done on the wall because it does not move. However, depressing a letter on a computer keyboard requires work.
omg, i wish my teacher could explain physics like you! i'm gonna drop outttt.....loollllz
i love you P. Dave
Thank you ser for helping me out
Love the intro.. 💫💫
Thank you.
U r amazing Dave😊
really very helpful love u professor DAVE
Hi,
May I ask which mode should be used when there is an angle given? I have seen some used degrees and some used radians. I did try using online calculators and got different results.
Thanks!
You need to look at the units on the angle given. There will usually be a degree sign if it is in degrees, and if it is in radians, it will usually contain pi and no unit specified (since rational number of degrees end up with pi in the numerator for radians). Configure the mode of your calculator to be consistent.
If your calculator doesn't have the ability to configure the mode, most likely the default mode is radians. Read the help text of the program or calculator to understand its conventions. For Google Calculator, type " degrees" after typing the number, as the input to the cosine function. This will override its default units of radians. For Microsoft Excel, type cos(radians(30)) to calculate the cosine of 30 degrees. The radians() function converts from degrees to radians, and Excel requires radians with no direct way to override its default.
I do recommend reading about what radians are, because they are a great angle unit that makes the Calculus of trig functions as simple and elegant as it an be. And I don't just mean learning that 180 degrees = pi radians, although that is an important thing to know about the unit as well. I mean learning a geometric interpretation of what 1 radian really is, and what motivates us to define the angle unit. Its name comes from "radius angle".
When we apply force to an object it'll cover infite distance (1st law of motion) but it actually nor happens due to friction so technically friction opposed the force we applied so how does it related to energy ? You doing the same work on rough surface and plan surface so how does you get kore tired there since you apllied the same energy
Do you have videos for conservation of momentum, radial acceleration, potential and kinetic energy equation examples? Please it would help a lot with physics
check out my classical physics playlist it's all in there!
Sir your teaching method is very easy and outstanding 🙏🙏🙏👍👍👍👍
He is amazing.... Want more
Thanks!
Thank you very much
Wow! your's voice is superb
hi great video, I thought scalars cannot be negative? (time stamp 2.37) did you mean vector?
Scalars can be negative. Some scalars make no sense as negative numbers, others are used as negative numbers all the time.
Some scalars make no sense as negative numbers, like speed, mass and volume. There are also scalars that make sense when using in relative scales, like temperature, pressure, and elevation, but ultimately are positive in absolute scales. Additionally, some scalars are defined in with an arbitrary zero point is, and thus can be either positive or negative. Potential energy, and related concepts like voltage, are examples.
Beyond that, there are scalars that have a nature to make sense in both signs, such as electrical charge. Work is one such example that makes sense as a negative number, because it simply means that the agent of the force receives the energy, instead of providing the energy.
@@carultch thank you for the detailed response :)
Thanks bro :)
The second law of thermodynamics (part of it) is that all physical processes create entropy and entropy the amount of energy not available to do work. It, along with the first law is the reason you can't create a perpetual motion machine, all the energy will "turn useless" which is the second part, that all the energy will become entropic in a closed system. Still trying to figure out entropy so that's why I bring this up.
yep it's a multifaceted law! can be expressed in a variety of ways.
So, if take the perpetual motion machine example, say a machine that (well, it doesn't succeed obviously) that is a closed system and tries to recycle the energy into itself, stops working, how? It's able to do it, initially, but then eventually it can't, what is going on? I'm trying to think of an example of something we could try to make into a perpetual motion machine that would obviously fail to do so, so I can try to figure it out. I'd say water that falls turning a wheel, in which the wheel pumps the water back up to fall on itself to turn it, but that's not exactly closed, because what starts the wheel turning in the first place?
A perpetual motion machine could exist in theory, if you were able to eliminate all losses, such as friction, viscosity, drag, and ohmic resistance. But the minute you try to extract any energy out of it for any application at all, it will no longer be in perpetual motion. You will slow down the motion, and deplete its energy.
What people really mean by "a perpetual motion machine", is really a more like a perpetual WORK machine. A machine that can continuously deliver a work output, without any work input. It doesn't exist in reality.
A planet in orbit around a star is one example of what would technically be a perpetual motion machine by the direct meaning of the words. But if you were to extract work out of the orbital speed of the planet to power your own machine, the planet will not keep orbiting at the same position. Its orbital energy will decrease, and its orbital radius (or more generally, semimajor axis) will also decrease. Continue extracting energy, and it will end up on a crash trajectory with the star.
Good Explaination. @
Cool video. Please make one on power also.
Sir as u said, work may be positive or negative..
But work is a scalar quantity
we just use positive and negative values to distinguish between work done on a system and work done by a system.
شكرا ❤️
thank you dave
Thanks for being a good teacher or that you're acquiring incorrect knowledge because that's what it is.
love your intro 🙂
Omg you are literally god thank you so much😭❤️
The definition of work in Physics as what happens when an applied force causes a displacement of an object is completely erroneous or wrong and work ,hence, is not really force times displacement(F•d). Work is a vector quantity(i.e. it's not a scalar) and ,in general, is defined as a "physical-displacement(ms)" by or due to a force, an impulse, or a kinetic force.
The work-energy theorem stating that the net work done on an object equals the change in the kinetic energy of the object is completely erroneous or wrong too. It would be the net force on an object that is equal to the change in the kinetic energy of the object.
Thanks poff Davy
This makes me think of the old expression every young man is scolded/initiated with into the world of manual labor:
*”Let the tool do the work!”* - so.. the reason why we quickly came to realize just how wise this initially irritating/inane advice really was, is because according to the laws of physics work-energy theorem: We only do the work of changing the kinetic energy of the tool, but only the tool’s energy of motion can now do “the work”.. so ya, let the tool do the work!
thank you
Super teaching sir
thanks you are super teacher
Tnx sir g
good explanation
thnx
Thank u
thanks dude
You the best