Physics - Pully on an Incline (2 of 2) With Friction
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- เผยแพร่เมื่อ 20 ม.ค. 2013
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This lecture will cover Newton's Second Law: F = ma.
Problem Text:
A 5kg mass is placed on an incline with friction making an angle of 30 degrees with the horizontal. A rope is attached and positioned over a pulley at the top of the incline. A 6kg mass is suspended from the free end. What is the acceleration of the system. Assume the coefficient of friction is 0.2.
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I appreciate that they left in the part where he gets frustrated with his calculations not adding up. It's encouraging to know that even the best can struggle with Physics.
+Stefan Bekker I did cringe quite hard tho. Physics cringe compilation may 2016(ap test times of course)???
ha gay Oh, so you've never cringed after making a mistake?
nah only dumb people struggle at physics
AliGay Nice guys... I don't get too heated at a fellow student(or even teacher) for making a mistake or there, especially if for that one mistake there's a million times they've solved,plugged, memorized, derived and experimented flawlessly.
Also, why are you watching a simple tutoring video about algebraic physics if you weren't 'struggling' a bit? I mean cm'on. This is easy stuff(This paragraph is satire boys. Think Samuel Clemens on this one.).
Stefan Bekker you are damn right man
I love that you didn't edit the frustration out. Shows that it's normal to be drained by a problem and you just gotta keep plugging away at it.
Yes, I too get confused at times, until I can get my brain unstuck.
"my mind is not on this"
same
wow sir, your explaination is simply the best of all, even better than khan academy. your pace of teaching isn't too fast nor too slow and the way you explain makes everything so much understandable in the name of physic. Please continue to upload videos. Thank you so much!.
+Thy Nguyen Nah fam. Khan academy is a new level. You can't compare
That is my opinion
+Thy Nguyen well your opinion is wrong. don't give wrong opinions
+Danish Ashar wrong about?
+Danish Ashar kid, if you dnt like what i say you can fk off :)
You absolutely blow my professor out of the water. You are so much more clear with all the steps you take and it makes understanding the topics much easier. Thanks so much.
I just wanted to say thank you for making these videos. You may have single-handedly saved my Physics grade. You make it so much easier to understand than my professor and the way you break it down and explain it makes sense to me. You've earned a follow from me for sure.
Thank you. We are glad you found our videos. :)
He wanted to start again respect for a perfectionist
well at 7:00 I learnt not only Newton's Law but also "Perfection is Imperfection"
the dopest Professor! Thanks ü
Professor van Biezen, your videos flow so effortlessly, at such a smooth and steady pace, and I have been watching one after the other, so it was not until the moment of frustration we see in this video that I finally wake up to all the work that you and your helpers must put into making one great video after the other. There are so many videos, and they are so good!! Yours is the best science/math channel on TH-cam! I want to thank you for taking the time (and these must have taken you SO much time) that you have put into sharing your excellent teaching style and knowledge with us all, and the effort that you have made to do so. I don't know why you do this other than to help those of us who are struggling to learn. Thank you so much!!! Kudos to you, Sir!
PolyPixel,Thank you for this very heartwarming comment. Yes, between my wife and I we have invested 7500 hours of our time into this venture and it has grown far beyond our expectation. Every one of us has been given a skill and we believe that a big part of our life and existence is to use that skill to give back to society in response to the blessing of life that we have received. It is great to know that these videos have helped many thousands of students around the world.
G-d bless you and your wife and family. I owe you a debt of gratitude. All the best for continued success in your teaching endeavors and everything!
His videos are so amazing, and it is very refreshing to know the reasons behind equations! My physics teacher barely explains anything, and jumps all over the place without telling us why.
Murathan,
g = 9.8 m/sec^2
g is the acceleration due to gravity, experienced by all objects on the surface of the earth.
Weight = mass x g
or w = mg
weight is a force and therefore, mg is the force pulling an object with mass m to the Earth.
I like how you explain this. You're going at the perfect pace and it's really helpful. Thank you!
just wanted to say thank you for explanations. You have helped me understand physics better than any other book or teacher. Keep up the great work!
First of all, thank you for the great explanation. Second of all, the bit where you have a calculator issue was hilarious and I applaud you for leaving it in. Bravo good sir. I learned something today!
6:53 my reaction everytime i press my calculator.
nevertheless, the best account for teaching physics so far!
you sir, are awesome! I almost cried watching your videos, I really appreciate people like you who explains things so simple and such organized manner! This is what makes learning fun! kuddos to professors like you! 👏👏👏👍👍👍
Thanks Michel, your way of explaining has improved my understanding.
good job sticking with the problem. I saw it...I'm glad you took a second to see it for yourself.
at 7 minutes, that is me with every physics problem. :P
That was before we learned how to edit videos. Now we'd just edit it out. But it is kind of funny. XD - Editing "Crew"
You make physics a lot easier ! THANKS SO MUCH !
I was able to perfectly understand both parts. These videos are excellent, and you are an excellent teacher. Please continue to enrich the science education of others the way you did here. Physics and Math and their related fields are often seen as too daunting, and it's heroes like you that make them accessible to those who would otherwise believe they don't have the brains to do them.
Thank you! 😃 We are glad you find these videos helpful!
Thank you Sir.It helped me a lottt.You made the difficult things very easy to understand.Am grateful to you.
If the pulley has mass you must solve the problem using the moment of inertia of the pulley. Instead of F - m x a you must use Torque = moment of inertia x angular acceleration. Look at the videos on moment of inertia. There are some examples where the pulley has mass.
What happened on 7:00?
Laurelindo
It looks like the "editor" didn't take out that part of the video. (oops) This is one of the early videos that we made. Notice how they didn't all go that smooth.
Laurelindo LOL he forgot to multiply the numerator by gravity. He didn't mess up on the board, he just plugged it in to his calculator wrong.
Quick editing tip. Even in TH-cam, you can fairly easily trim out the bit in the middle where you stumbled on the calculator. Thanks for the videos!
David Learmonth
I actually kinda like bloopers like that, I am not bothered by them at all and gladly watch the events unfold! =D
They also show that even professors can make mistakes.
Love you videos! Just came across them with a physics exam tomorrow... Big help!
Thank you for explaining it so simple.
i love the way you explain. really my mechanics became a lot easier.
By far the best video on physics that expalins everyhting......m ready for this part of the test (TEEHEE)
I love this moment of despair! We are all human, aren't we? ;-)
Sjaak,
I wouldn't elevate it to the level of "dispair", but you can see that I have my moments that my brain gets stuck and I can't see where to go next. That makes understanding it afterwards so much better. Yes, we are all human.......
:) I agree with you Dr, we must keep going and trying until we success
I would like to thank you because I was in a crying panick attack because I did not understand anything and your video was the light of my night. I wish you the best of blessings in your life and in your families life. Thank you.
Thank you and we are glad we could help.
Really useful lessons, please keep on going sir you are aiding the education of a lot of students!
Very clear ! Congratulations and many thanks from Santiago, Chile
Thanks bro. U make it so easy when u break it down to just each force opposing the other without adding extra stuff. bless
Glad to help
This video helped me so much! Thank you
You are much better than my professor
You make everything very easy..Thank you so much.
Really great explanation to help with reviewing!
Thank you very much ,
You make everything easy,
you are the best.
It's great. I have no other words to say !
clear , easy . thank you for your explanation .
Dear professor Van Biezen, thank you and your, beautiful supporting, wife. I wish I could express my gratitude, for helping hundreds of thousands if not millions of students like myself, even more. Your efforts in making these videos and the encouragement your wife gave you is a symbol of your good intentions. I wish you both nothing but happiness and success.
Thank you Mahammud, we really appreciate your comment.
Great video, easy to understand
Mass m = 90.8 kg sits on an inclined plane that makes an angle α = 25.3o with the horizontal. A massless string is tied to m, passes over a frictionless, massless pulley, and is tied to mass M = 56.8 kg hanging on the other end. Assume:
- the coefficient of kinetic friction between m and the surface of the plane is μs = 0.269.
- the string is parallel to the surface of the incline.
If m is initially moving up the incline find the acceleration (magnitude in m/s2 and direction) of the system. (To give direction: give the answer as positive if the acceleration of m is up the incline, and negative if the acceleration is down the incline.)
it gives 0.31 but it says its wrong, do you know why?
great video, my left ear is very thankful for your help
hahahahahahah
hahahhahahahaha
sir u doing a fab work... u got struck fo a while... doesn't matters at all! i love the way u spreading knowledge!!! keep moving ahead... love u sir
Mike
Sir you are the best..
Thank you for these videos
You make learning sooo easy :D
Cheers !
This is very helpful. Thank You.
Really helpful and informative, thanks a lot
Thank you so much sir crystal clear explanation!
A block rests on a plane that is inclined at angle of 30degrees to the horizontal. Coefficient of kinetic friction between the block and the plane is 0.2 . if the block had a mass of 10kg and a man wishes to push it up the plane :
(a) what is the direction of the frictional force?
(b)what force parallel to the incline is necessary to keep it sliding up the plane ?
(c) what horizontal force would be required to push it up the plane ?
I love this man.
Sir thank you so much
I finally understand the different relations
how do we judge the direction of motion before starting the problem? We get a different equation if the motion is assumed to be in the opposite direction - i.e. if the mass on the incline is going down. in that case a = (m1+m2 sin theta - m1cos theta * mu) * g / (m1 + m2).
Thanks u so much sir.... God always with u... Stay blessed.
Enlightening lecture!
However I would like to recommend using the value of 'g' as 10 m/s^2 just for easier calculations and explanation.
Thanks.
Thank you for this!
Very helpful Sir. Thanks you very much.
This is an excellent explanation
Thank you. Glad you liked it. 🙂
Really amazing jobs explaining it!
Glad you think so!
Thank you very much for this wonderful video! help me a lot on figuring out this type of problem..
Great! Glad you found our videos! 🙂
You have helped me so much it's ridiculous!
Thank you :)
Thaaank you so so much! Amazing explanation .
what is we were asked to find the tension of the string?
l now understand better. THANK YOU Sir
Im a fan professor, great teacher
Thank you
your explainations are so clear sir . i became more powerful on solving problems . thank you so much sir
Good for you. Keep up the hard work.
sir it is very clear for me now I can solve any pully problem thank u sir
Thanks for the videos. My teacher is awsome but this really helps.
You are too great sir I love the fact that u portrait a good quality teaching sir
and that moment of despair change my way of thinking it really great u didn't edit it sir 🥰😋
A question on the tension
I can't picture a situation that the pulley that will have a mass and how it will affect the tension on the system
We have several playlists with examples like that. See this video: th-cam.com/video/qu46xL4KPvU/w-d-xo.html in the playlist: PHYSICS 13.1 MOMENT OF INERTIA APPLICATIONS
it is very very very very very very very clear thanks very much
You are most very very very very bery welcome!
thank you so much this was incredible
Glad you enjoyed it!
+Michel van Biezen hey but there is a slight confusion. you gave a coefficient of friction right? but you need to make it clear whether it is a static or kinetic. for the question we need a static coefficient.
+Robel Fitiwi Since the objects are in motion, this is kinetic coefficient of friction.
+Michel van Biezen , okay if you take it as "kinetic " , try to use the static friction if it makes the object move . Unfortunately, it won't make it move .
+Michel van Biezen which makes using kinetic friction zero percent necessary.
I mean you literally can't get acceleration because it won't move .
Well just give it a little push with your hand and the system will move, and the rest is just as calculated.
I really appreciate you thank you
You are welcome. Glad you found our videos!
Hello professor, I just started taking dynamics and since we have to break up forces into their x and y components we also need to account for the x and y component of the Friction force, which never really happened with kinematics
On an inclined plane, the components of the forces are written in terms of the parallel and perpendicular components (relative to the surface of the plane).
Thanks again.
He became so relatable at 6:55
"My mind is not on this.." Me: Same energy. BUt thank you so much for this videoooo
forgot to edit out the short period of frustration at 7:02
I'm glad that's in there. Real people.
Agreed.
Thanks very much sir.you have help me so much for am having exams of the same things.... watching from the university of Zambia
Wow, it is great to welcome you to the channel!
love you video .thank you somuch
Thanks for watching!
Very very helpful
Thank you very much good sir.
Good sir, I owe you!!!
Glad to help 🙂
i love you professor
MvB thanks
Thank you
Hats off sir u r. The bestest
Thank you, I am glad you think so
Thank you sir!
You are welcome!
I love the 7:00 part, cuz I just realized that I'm not the only one always in panic when doing Physics haha
hi Mr. Michael . congratz for your very helpfully chanel. i really like your work. im and arquitecture student. i would like to know how to calculate the mass "ma" without acceleration. thanks
You are great! Thank you
Thank YOU!
Far from it, but we are glad you like our videos. 🙂
I am working in an experiment where I placed a car on an inclined, the car is attached to a string and the string passes through a pulley, the string is holding a bigger mass that is pulling the car to the highest point of the inclined. But we measured the tension of the string with a sensor as we held the car to avoid moving. Now I have to calculate the Tension applying Newton's First Law and compare the theoretical Tension with the measured Tension. Where I am struggling with it is with my diagram, I don't know if I have to include the force I am applying onto the car. Any tip would be appreciated.
That seems like a dangerous experiment. You should be able to find the information you need from these videos.
Beautiful man
Thank you kindly
This is comparatively simple. Mechanics is not that hard. Just have to be careful. Thank you sir, and please keep it up.
That is a good way of putting it. "It is not that hard, but you just have to be careful". Great comment.
AMAZING !
Thank you!
I seriously think all he needs is a real calculator...
this video is amazing.Can i ask why did you subtract force of friction although it is acting in the same direction as that of acceleration? Thanks!
If you look at the drawing, you will see that the direction of the friction forces is opposite to the direction of the acceleration.
thanks!
Love you man I love you
Wow Michael!
Well explained.
But why did you multiply the costheta with the friction only and not the whole sum of the forces?
In the numerator, we have 3 forces. One that aids the acceleration, the other 2 oppose the acceleration. One of those 2 is the friction force. The definition of the friction force is that it is equal to the normal force (mg cos(theta)) x coefficient of friction (u).