Mechanical Engineering: Particle Equilibrium (11 of 19) Why are Pulleys a Mechanical Advantage?
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In this video I will calculate and explain the mechanical advantage of using pulleys.
Next video in the Particle Equilibrium series can be seen at:
• Mechanical Engineering...
How can someone dislike such knowledge transfer ... and for free ??? This is such a great physics teach ! Thank you Sir. !!!!!!!!!!!!!!!!!!!!!!!!
Missclick I guess
Many of the dislikes, if not all, sometimes, are from TH-cam itself. Believe it or not, that's the truth.
YT has no interest for a video to get only likes. So they keep the balance "right".
Physics haters I guess
I’m convinced there’s a small percentage of people out there which are always acting as trolls. They thumbs down everything no matter how good it might be. Think Joker... they just want to watch the world burn (but all they have the balls to do is thumbs down some videos lol)
I do not dislike the premise(free knowledge transfer), but I do dislike this video because of the methods he's chosen to explain this concept. Just iterating through different pulleys by calculating tension is not teaching physics, its doing algebra. Its lessons like this that make physics seem dull to certain populations, and physics is not dull.
Here are some concepts I would've loved to see elaborated on: Why is the weight sometimes attached to the rope & other times attatched to the pulley? How does the tension in the rope fixed to the structure change through the presented configurations? What movements in the system result in the operator having to pull more length of rope in configurations with more mechanical advantage?
I'm 64 and NOW I finally get it 😁
Thank you!
I am still learning new things every day myself. :)
I'm 52 and I studied this in school but forgot how it worked. Now I'm going to remember how it works forever :D
OvalWingNut, I am 65. I wish that I saw this lecture last year.
@@SharpObserver1A Talk is cheap.. Let's see your video with a better explanation.
@@SharpObserver1A Yeah, but the 99.99% of us here watching interesting physics videos mixed in with funny cat videos really don't give a sh!t.
I am a retired 82 year old electrical engineer and this helped me review some of the material from a Statics course that I took many years ago! Thanks!
Statics is more important for civil engineering than for electrical, I would think.
When my teacher tried explaining this to the class they didn't mention that you would have to pull it longer for each pulley. Saying that helped alot thanks
Distance x Force = Work. This means that "moving" pulleys allow you to do the same work with less force with proportionally more displacement. Fixed pulleys work differently.
@@albertoolmos21 How are they different. I just assume he drew the pulleys separately to show how many ... that the point of axis would only be in the free body diagrams.
@Glenn Heiselman Yeah ... in my youth my dad had a 2/3 or 3/4 rope pulley. Meaning 2 or 3 pulleys on top and 3 or 4 on the bottom ....
and it felt like, when I had to roll it up, a mile of rope.
Cullen, with simple machines, it's always distance that gets traded for increased mechanical advantage. Levers are the same. If a lever has one side 4X as long as the other side (measuring from the fulcrum) it will have 4X the mechanical advantage (i.e. can lift 4x its input force) , but must travel 4 times as far. With hydraulic systems, same idea. The input 'piston' must travel however much the larger (output) piston is. Ex. if the input piston is 2 sq. inches in area, and the output is 8 sq inches, the input piston must travel 4X as far.
One question :For example , he only explain the tension force between two point of the pulley connecting to the object , what about the tension force on the other pulley, for example, in the second example, the one connecting to the object is 50N, but is the other one tension is 50N is too or not?
I’m truly thankful for your content, i’ve aced at least 4 courses in uni just because of you, now graduated i owe a big part of this to you
Congratulations! You owe it to your hard work. We are glad we could be part of it. 🙂
You study this at Uni ?? Gosh levels have gone down dramatixally this used to be junior High School Physics class. In University you should study mechanical tensors. No wonder the younger generation have gone dumb.
@@ericastier1646 Yeah, I learnt this in my second year in Highschool. Not only this, but beam design, polar diagrams, HP, torque etc. What the hell is happening to the youth of today???
@@Kysushanz A lack of strict discipline, a lack of respect for elders and a degenerated media and technology that has been commercialized for bad purposes (the smartphone = dumbphone). Meritocracy is disappearing, it's why learning in school has been devalorized. This is due to the influence of floating currency attributable to the jews.
@@Kysushanz dude, i learned AP calculus when i was barely able to chew yet, u guys are pussies ngl
You truly are an epitome of a professor. So effortless and amazing. It's a joy watching your videos. Thank you so much sir.
I'm sure there are university students out there who spent 90+ minutes on a lecture for this to be explained poorly, while this man tells it in 5 minutes so clearly my 7 year old sister understood it perfectly.
Your ability to teach is superb! You're clear & mention the little details which greatly improves understanding. This video helped me more fully understand a problem where a pully had mass. Thank you.
THIS IS A REAL ADVANTAGE FOR THE STUDENTS INFLICTED WITH THE PAIN OF COPYING THE AFORESAID PROBLEMS WITHOUT HAVING A SLIGHTEST HINT OF WHAT THEY ARE COPYING.#AMAZINGWORK.
Better explained than my physics professor at the university
Are you university in uk in america, I'm just curious.
@@spazmoidectomorf6209 He made that up. He lives in a basement.
@@jamesd7700 lol, I know, I just wanted to know how the syllabus varies from uni to uni and from country to country
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Dont degrade your teacher.
I am an Indian and at first I thought that it might be hard for me to understand but I dis it.. Thankk you so much sir!! MAY LORD SIVAH BLESS YOU!!
Thank you. Welcome to the channel! 🙂
This is how it's done, people! Superb approach. Clean, clear opening diagram. Four examples for comparison, right in front of us. Quick overview, then right to it. I rarely enjoy teaching on the internet, but this is impressive.
Thank you and glad you enjoyed it!
People forget how amazing these simple things are and how efficient they are. Still used today in all our construction projects. Cranes are just giant pulleys.
Good observation! Yes, they are used in many applications.
This teacher saved us and got us through physics30 in 30 days. It was an intense schedule and this TH-cam teacher was the best resource. Wish he was my teacher in life. Thank you Sir!
Glad you found our videos and you found them helpful! 🙂
I am 36 years old. In my high school years ,No one understood this lesson to me that way. Thank you very much for this practical information. I wish you continued success.
Thank you. We are glad you enjoyed the video. 🙂
It's been so long since I did physics, this brings it all back, I had forgotten how simple pulleys can be so easily calculated
50 years ago I took a year of college physics. Your style is very similar to my professors back then. Great presentation! Thanks
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You make it seem so easy. Thanks professor/teacher.
Thanks, Michael van Biezen for your pully power demonstration. I am no Brainiac yet I can learn the principles such as you have narrated for us per the above video to understand the importance of each required principle.
I am inspired.........
Your articulation is fabulous...
sir you are no less
Sir your not less then him
@@azaanahmad6265 m
@@azaanahmad6265 .
@@azaanahmad6265
Thanks
Very good explanation. I studied this many decades ago and this was a good refresher.
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I was introduced to this channel in my 3rd yr in Engineering School. There is so much to learn in these videos, and it is well explained. Thank you for your lectures, good sir! You are a hero! :D
Thank you for sharing. We have put a lot of work into these (9500) videos and we appreciate this kind of feedback.
After watching other videos on pulleys I get a basic understanding. But I found myself asking “But how or why?” No one explained that part of the pulleys. Or did that it didn’t register with me. But your explanation left me with my question answered. You’re an awesome teacher!!!
I am working on a pulley system for an antenna tower. I needed a refresher about pulleys learned back in my college days. You're explanation was fantastic and actually helped me remember things I had forgotten. Thanks! --Steve
Glad I could help
Very nice job. Your video acting ironically as a set of pulleys and I was able to lift the load of the understanding which I couldn't figure out before, and deposit it into my head.
Thanks
😂🙂😂
This guy is one that can be surely said as a Very Nice teacher.
All you need is a good teacher. Thank you Sir!
Awesome lecture! I wish I found these lectures years ago when I took introductory mechanics so I would've loved and appreciated it more.
Glad it was helpful!
Seriously, you brought me through my Engineering Degree. Thank you for ALL your videos.
Thank you for sharing. All the best to you.
Beautifully explained, to the point and simple. Thank you.
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Best video to learn about Pulleys
Thank YOU
I always wondered how a pulley works. Thank you!
Great explanation! Now, i need to get an understanding of how to actually rig pulleys in a series like that.
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If it help you can visualize it as two pulleys with multiple wheels on a common axle where the smaller wheels are behind the larger ones from a side perspective.
Nice to see this explained as I have always just took pullys for grantedmm Thanks
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Wow!... Clearly a good example. Thanks a lot, Professor!
Thank you Doctor....You are a great instructor/Teacher.
I... I might actually have a chance of passing my ASVAB test now... thank you so much sir, this is amazing
All the best
Все понятно. Спасибо!
Clear, efficient without any unnecessary blabla, Brilliant!
Thank you. Glad you liked it! 🙂
Fantastic, unbelievable explanation, thanks sir... 🙏🙏🙏
AT this point, we can learn everything we need to know right here on the internet from brilliant people like this guy....200k for college? I dont know...i hope that requirement (societal requirement) changes sometime soon
200k is only for the "official" little paper at the end.
Yes and no certainly I agree that college is over priced and you can learn almost anything from internet sources, but you may not know what you need to know. I think there is still value to an institution that defines what knowledge is required for a particular field and requires a proof of understanding
I know it’s probably the norm, but I am so happy to see the metric system in an US physics video
You're welcome 😊
Dr. Stone brought me here. If only I had watched this in high school. Now I am working as a software engineer and I don't need to use this information about pulleys but watching the Dr. Stone anime made me interested in science again and a lot more. I highly recommend that anime if you are interested in science
Very nice, simple explanation of these principles. Thank you so much for sharing your expertise. You would have been one of my favorite professors!
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If with no formal training you understand the theory, principles, function and use of mechanical advantage then this should be a breeze to grasp. Sometimes, with no formal education necessity forces one to discover ways to make work less burdensome. And the lever and pulley are the perfect place to start.
I just have my JEE entrance in a few months and this helped me revise my Atwood Machine dynamics in a single go, Thanks a bunch Sir 🙏✌️✌️
Good luck on your JEE test!
Got postponed right ? To June
@@82h4dheu6 August
@@eternalmangekyou968 Advance august
And mains June and July
Btw I'm jee 2023 aspirant
@@82h4dheu6 best of luck for it , im not pretty much mains oriented , it's rather a way for me to appear inthe Advanced paper for which I've prepared for 2 years
Best video to learn about Pulleys
Thank you .
Thanks for a simple, straightforward explanation with nothing omitted.
You're welcome! Glad you enjoyed it. 🙂
Seems a lot like a lever and fulcrum. great video!
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I mean in the sense that you can multiply a small force by applying it over more distance I guess so
God bless humans like you :)
Thank you, sir. You have been the reason for my understanding of many issues that help me to finish my major and now i have a double major diploma in biomedical and electrical and electronics engineering. Thanks alot sir i really appreciate your efforts 🙏.
Congratulations! You have accomplished a lot. We are glad to have had a small part in it.😃
You made it much easier to understand, and within a short time.
I'm curious about the forces applied to the line itself in these MA systems. According to the laws of pulleys in example 2, you could lift 100 newtons with a line that was only rated for 50 newtons? The work is being done, in my mind that 100 newtons of force has to be acting on the line in the middle of the lower pulley.
It's 50 Newtons pulling to the left balancing 50 Newtons pulling to the right. So the tension would be 50 Newtons (ignoring the traction on the pulley and stretch as the weight is applied.)
That was brilliantly done sir! You taught me something in 5 minutes that I had failed to understand in 3 days.
3 days? I didn't understand for a month
Mechanical advantages are often only advantages in theory. We neglect the friction to make the calculations easier. Suppose we are to rescue a climber who has fallen down a cliff, the person weighs 90kg and we use pullys in a 9:1 system. Do we then only need to pull with the power a ninth? The friction in the system cannot be neglected. Climbers use dynamic ropes to avoid injury if they fall. Let's say the person in distress has to be lifted 10 meters, there will be a lot of rope to stretch before we even lift anything at all. So in practical cases it can happen that we get a better mechanical advantage if we instead lift the person with a 3:1 system. Your calculations are a good starting point for describing reality.
We first learn the principles of physics by ignoring things like friction and wind resistance. Then once we understand the principles, we add the compexities of wind resistance and friction. (We have videos on ropes and friction in the mechanical engineering videos).
Thank you sir. t had been a problem for me to understand how pulley works in AP physics, now you clarified it to me.
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Great,thank you master.
Hiii
Follow me on instagram babar Asif 000
Professor Van Biezen: another excellent video, I really enjoy your channel, and have become a monthly donor.
Another interesting aspect of pulleys, and please correct me if I’m wrong, is that the up forces must equal the down forces in the scenario in the above video. For instance, on the first pulley system, the total “down” forces are the weight (100n) and the pulling down force of 100n. Which means the ceiling is actually supporting a 200n load.
In the fourth setup, the total down forces is only 125n, therefore the load on the ceiling Is only 125n
So, in addition to the mechanical advantage in “pulling” the fourth setup actually reduces the load on the ceiling, correct?
You are correct indeed.
Force on celling in each cases are respectively-
1- 200N
2- 100N
3- 66.67N
4- 50N
just draw the FBD( free body diagram) for pulley attach to celling for reaction given by celling . Dont account 100N block in this case.
ashraf khan not sure where you are getting those numbers from, as they are only part, not the total. System is in static equilibrium. No accelerations are occurring. Sum of all torques must equal zero AND sum of all forces must equal zero. Up forces = down forces.
Down forces are the weight and whatever down force I’m pulling with. Ceiling supplies up load.
If I was to put a spring scale between the final (top) pulley and the ceiling, the spring scale would show:
1: 200 N
2: 150 N
3: 132 N
4: 125 N
Imagine in the second example, a 50 Newton person was hanging on the rope, not touching the floor. The 100 Newton weight is also not touching the floor. The FBD of the top pulley has a force pulling down of 150 N and a force, provided by the ceiling, in the up direction of 150N.
The force distribution would be:
50 N on the right
50 N in the middle
50 N on the left
@@foxhound1008 my mistake i forget the force due to the secondaries pullies in FBD of primary pulley(attach to celling).
Short and clear explaination of problems that we'ven't a Solution.....thanks a lot Sir!!! Your concept is very valuable💪💪💪
Pleasant demonstration ... with metric units. Merci pour le partage
Thank you sir. I was a little bit confused on this.
Thank you it’s very clear the way you x plain it
3:29 The reason you have to pull the rope 2 meters to lift the weight 1-meter can be understood in the following way. Since there are two ropes supporting the weight both ropes have to be raised 1-meter when the weight is lifted 1-meter which is a total of 2-meters. That means the rope you are pulling must be pulled 2-meters, 1-meter for each of the two ropes supporting the weight. The same is true for 3 ropes, 4 ropes and so on.
It also makes sense when you consider the work done in lifting the load. The work is the same (minus any losses from friction of course) in our ideal case no matter how many pulleys you use.
Work = force X distance, so exerting half the force means the rope must be pulled twice the distance. The number of ropes supporting the load is the mechanical advantage. Divide the load by that number to get the force you must exert, and multiply the distance the load is lifted to get the length of rope you must pull.
Nice input.
@@MichelvanBiezen 33 years teaching Physics has a few benefits (getting rich is not one of them). LOL
HaHa, yes indeed.
Thank you, that was so well taught that not only do I now understand pullies better but it makes complete sense to me
Thank you for your comment. Glad it was helpful 🙂
so, 100/1, 100/2, 100/3, & 100/4 depends on the number of string. Better explanation than my univ prof haha
Nicest video about police I have ever seen.
Thanks .you always give me an answer to my questions
Straight to the point, clear and well presented. LIKE!!!
I'd like to see the force on the top-most pulley 'hanger'. It seems in the first example, that the attachment to the 'ceiling' has to support 200 N, the second only 150N, 133-1/3N for the third, and 125 N for the final example?
So having more mechanical advantage just happens to also lessen the needed strength of the attachment point?
that's antigravity know
In reality the ceiling would also support the pulley weight.
Mr. (Dr?) vB can answer authoritatively... but my thought is, the ceiling always supports 100N. Based on the assumptions, the pulleys weigh nothing, the rope/cable weighs nothing... weight at the ceiling must be 100N. That said, I expect there may be some exception between the time force is applied by pulling down, and when the pulley(s) / weight actually begin to move... I see where you’re coming from - if I am pulling on the cable with 100N, and the weight is 100N, then the ceiling must be holding 200N. Now I have a headache. Engineering school was way, way, WAY too long ago...
why am i going to uni when your free content is better?
Yo wut Triggered much?
Yo wut Thats just liberal arts people. Theres more reasonable people in STEM in my experience.
Yo wut Thats just liberal arts people. Theres more reasonable people in STEM in my experience.
Thank your very much for this , thought i studied the whole chapter i could't understand it because i was taught using variables using numbers is a huge gamechanger !
Using a simple example with numbers often clarifies things tremendously. Glad you liked it.
I noticed this is 8 years old, but I had to comment anyway: If you factor in the efficiency of each pulley (frictional losses), you may no longer get mechanical advantage after about 5 lines. If a pulley was .9 eff, then it would take 110 lbs of pull to hoist 100 lbs of load. A spread sheet will show that the pulling force no longer decreases when continue to add lines and pulleys.
Yes indeed. That said, pulleys heavy very little friciton and do not require that much energy to rotate them.
Şekli ortadan böl. Yük /Kuvvet kolu hariç diğer ip sayısı
Well, yes ... but. "You can draw a free body diagram around the object you are pulling up." That is not explained well because by the time you get to the end, that free body diagram is not just around the object you are pulling up but is drawn around the object itself and 2 pulleys. Why? Why not draw the free body diagram around all 5 objects? The explanation of that would add complexity to the presentation and would probably cause the students to scratch their heads.
That is brilliant and simply explained, I have never understood how the pulley system worked, now I do, thank you!
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Awesome teaching video. That way of transferring knowledge not only help students understand theories, but also make them curious, love and study creatively. Thank you!
Thank you for your comment.
Some teachers are just better, that would be you sir.
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Sir the idea that something is hanging from the middle of the pulley makes zero sense to me unless that point rotates.. can you briefly clarify it?
Nicely explained, thank you.
This is the best approach I've ever seen for doing pulley problems.
Thank you. Glad you liked it.
@@MichelvanBiezen : )
I don't often condone witchcraft, but when I do, it's this channel.
We all share your concern with being caught up in the Dark Arts , but I have all confidence that within the century science will discover a perfectly rational explanation for this gravity defying allusion and trickery.
Dr. Stone teach me this
This is very helpful. I have a question if you are willing?
I am building a home climbing wall that can adjust the angle of overhang. This adds considerable weight to the existing building. So, instead of a ceiling, I have drawn (not built) a series of pulleys that allow the wall to change angles. The goal is to not overload the building structure, but I do not know how to do the calculations. The pulleys do not function as this tutorial (moving straight up and down). My pulleys would be anchored into a concrete floor, go up to a beam, and then out and away from the building to movable pulleys (wall is moving so the pulley is also). My intuition tells me that some of the force must be exerted down and the other force out and away. Any help would be appreciated. Wall is hinged at bottom. I could send drawing if that helps. Even if we made some basic assumptions this would greatly help do the calculations.
Great explanation, easy to follow and straight to the point. You are a great teacher.
Thank you. Glad you found our videos! 🙂
Atlas: “Interesting...”
@William W. Campbell-Shepherd IX probably constructing a pully with a mechanical advantage so large that he doesn't need to spend energy and pain holding up the world, he can just tie himself down and lift the world
To pull the 100N object up, wouldn't you need a force >100N? Just asking...
Only with the pulley on the left. You need less force for the other pulley combinations.
I reread you question and understand what you are asking now. You only need a force > 100 N momentarily until the object begins to move. Then only a force = 100 N is needed to keep the object moving at a constant speed. (Newton's 2nd law)
@@MichelvanBiezen Bodies in motion tend to stay in motion, bodies at rest tend to stay at rest... Thank you for the responses.
Entropy always gets paid.
It looked so intimidating, but ur simple explanation rly made things clear. Thank you!
You are welcome.
Fantastically simple explanation, thank you
if he was my physics teacher i might have solved every pulley question in JEE
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I learned to just count the number of pulleys so you can say 1:1 or 2:1, 3:1, 4:1 etc. so you know the ratios.
Interesting information, thank you.... Big Like)), but in order to calculate the correct force required, do not forget the weight of the pulley (s) as well as the cable or rope that increases and decreases its weight according to the direction of movement.
Very interesting lesson making it clear regarding pulleys and lifting
Archimedes lifted a warship with his own physical power using a complex system of pulleys!!!!
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I understand the math and physics, but I can’t come up with a verbal explanation of how and/or why it works - except to say, “magic”.
The principle here is that the work done pulling on the rope equals the work done lifting the object. W = Force x distance and if you half the force you must double the distance.
@@MichelvanBiezen it still sounds like it exploits physics to me
What isnt mentioned here is the ceiling that is holding everything up is exerting an equal and opposite force to hold everything up. when you pull on the rope u are exerting more force on the ceiling in order to lift the object.its like having another person pull the other side of the rope.
@@danielgudi7446 If you write what exactly sounds strange, I think someone here can give you a solid, direct answer to the issue.
@@jensdanbolt6953 I know that you trade travel way for force and you can use your own body weight as force instead of having to lift yourself up as well as the load.
The second point is a big advantage on it's own but I don't really get how the first point makes any sense.
I know that it is a meme that people compare everything with video games but that just sounds like a big to me
You are really a great professor, thank you very much🤩
Excellent explanation! Well done sir. 👍
Amazing!! Would recommend 100%. I think I gained my first brain cell!
Protip: try matching your outfit, particularly your bow tie.
Then:
Meh... school is boring, lets sleep.
Now:
Ohh let's watch a physiks class.
sameeee lol. Mostly because instead of taking classes that I'm actually interesting in like engineering and physics I am forced to take classes like Spanish and gym.
Very good 👍. Now I understand. If all teachers are like you, then it will be exciting to go to class
Thank you so so much! Such an intuiitive to understand explanation, very helpful while I am studying for the MCAT, thank you!
You're very welcome! Good luck on your MCAT. 🙂