I love these not so intuitive answers to these types of physics problems that are so commonplace. This party trick has been around for years and yet few people can explain how it works with such elegance
Professor Walter Lewin, thank you for the explanation of this problem! Recently I watched your lecture 8.01 28 where you showed this demonstration 😊 I always wait for your new videos and watch them with pleasure 😇
My son is in 8th grade and he loves learning from your UA-cam channel. Math, Physics and computer science are his favorite. He wishes to meet you in person one day. Lots of love and respect from California.
Excellent explanation, my adorable professor Dr. Walter Lewin❤, and thanks a lot! Here I would like to add more: it is the only stillness of the water caused by surrounding glass surface tension ( the entire volume of the water that touched by the smooth glass interior ), along with the bottom part of the smooth paper, which then while holding with the hand equalizes with the Apple Force ( formerly gravitational force ), counteracting! The inside air volume doesn't create any effect of surrounding surface effect but only adds extra Apple Force ridden weight on the water which is less than one atmosphere pressure. And when you break the absolute stillness of the water that will cause an immediate break of surrounding surface tension, such as when you cause free fall of the glass, or you shake to cause it! The only biggest reason is surrounding surface tension as you hold it at stillness that holds and compacts entire volume of the water but only lower segment attract to the water for one atmosphere pressure. If you are able to lower the one atmosphere pressure from a enclosed room, you will find the magic!!!
Moreover, only specific volume of water surrounded and enclosed by the smooth and stillness encloser at firmly closed cover will act accordingly becoming one unit as a whole that transmits water resistance all through.
The card does not need to sag for this result. I did the experiment with thicker cardboard and saw no sag, but I do see a tiny separation between the card and the glass which I account for by surface tension of the water.
Very honest person before solving problems without any hesitation clearly said it is not my solution I have seen several solutions and selected this and changed some concepts to explain more clearly ❤
I don't understand...In class, at 801x, more than a decade ago, you told us that this would be because of the low static pressure created (in a very thin layer where cup wall touches the card) dude to the higher dynamic pressure, when the water tried to pass. This was the explanation you gave while explaining Total Pressure = Static Pressure + Dynamic Pressure. Just out of curiosity, when did you changed your point of view into this new version ? Why did you give up from the total pressure explanation ?
GOOD MORNING SIR Sir, you are the only reason I have started understanding physics and my 10th physics passed because of you.😇😇😇😇😇😇😇 THANK YOU SO MUCH SIR 🤗🤗🤗🤗🤗🤗🤗🤗
Hello, professor I have a question that HOW MANY SIGNIFICANT NUMBERS PRESENT IN 5100 Kg . According to HC Verma there is only 2 significant figures whereas S l Arora says there is 4 significant figures as unit is written so we count all the zeroes. Could you please solve my doubt.
Sir, Actually I have a question from physics. None of my professors and seniors could solve it. Would you please assist me with it? The question is: Derive the expression for the magnitude of magnetic field at a point P in the plane of a current carrying circular loop of radius "a" and the current flowing in the loop is "i" (P is not the center of the circle.)
only 3 people had the correct 3 answers. Problem 179 + solutions took me more than 6 hours work. It was a waste of my time as the problem was too hard.
Sir, Actually I have a question from physics. None of my professors and seniors could solve it. Would you please assist me with it? The question is: Derive the expression for the magnitude of magnetic field at a point P in the plane of a current carrying circular loop of radius "a" and the current flowing in the loop is "i" (P is not the center of the circle.) Sir, please make a video on this if possible, please.
Hello sir i am having a doubt that refractive index of medium is given by sin i /sin t but can't we say it as sin r/ sint is this correct?please tell 🙏
I mean for thin cylinders Longitudinal stress is = p*d/4t, And circumferential stress= p*d/2t, But l am having difficulty understanding stresses in thick cylinders, change in dimensions of cylinders due to these stresses, kindly explain
Hello sir, I am a new student in your channel, I just saw one of your videos last night. I am a jee aspirant and My condition is very bad in physics, I need you so much, What shall I do. Please help your student.
you have 2 options option 1: eat yogurt every day but *never on Fridays* option 2: Watch all my 94 MIT course lectures. Start with 8.01, then 8.02, then 8.03. Do all the homework and take all my exams. *I guarantee you that you will then do very well on the Physics portion of any freshman college or JEE exam* You will find all information you need on this channel in three playlists "Homework, Exam, SolutionsY & Lecture Notes". 8.01 & 8.02 will each take about 200 hours, 8.03 about 250 hours.
Really?I mean can't believe that solution... Is that difference really enough? I have to put numbers and check.. Also why does the why does it fall once it (the cardboard) gets wet
I love these not so intuitive answers to these types of physics problems that are so commonplace. This party trick has been around for years and yet few people can explain how it works with such elegance
Professor Walter Lewin, thank you for the explanation of this problem! Recently I watched your lecture 8.01 28 where you showed this demonstration 😊 I always wait for your new videos and watch them with pleasure 😇
My son is in 8th grade and he loves learning from your UA-cam channel. Math, Physics and computer science are his favorite. He wishes to meet you in person one day. Lots of love and respect from California.
8th grade and ur son already loves learning and studying that's some good parenting u did there
Excellent explanation, my adorable professor Dr. Walter Lewin❤, and thanks a lot!
Here I would like to add more: it is the only stillness of the water caused by surrounding glass surface tension ( the entire volume of the water that touched by the smooth glass interior ), along with the bottom part of the smooth paper, which then while holding with the hand equalizes with the Apple Force ( formerly gravitational force ), counteracting! The inside air volume doesn't create any effect of surrounding surface effect but only adds extra Apple Force ridden weight on the water which is less than one atmosphere pressure.
And when you break the absolute stillness of the water that will cause an immediate break of surrounding surface tension, such as when you cause free fall of the glass, or you shake to cause it!
The only biggest reason is surrounding surface tension as you hold it at stillness that holds and compacts entire volume of the water but only lower segment attract to the water for one atmosphere pressure. If you are able to lower the one atmosphere pressure from a enclosed room, you will find the magic!!!
Moreover, only specific volume of water surrounded and enclosed by the smooth and stillness encloser at firmly closed cover will act accordingly becoming one unit as a whole that transmits water resistance all through.
The card does not need to sag for this result. I did the experiment with thicker cardboard and saw no sag, but I do see a tiny separation between the card and the glass which I account for by surface tension of the water.
I just saw this channel yesterday... Thank u for such wonderful lectures professor...Really addicted to this channel..
LOVE FROM INDIA❤️❤️
Thanks for showing some basic problems in your videos. A lot of viewers were attracted by your 801 demo's. ; )
Sir you are the best physics teacher. One like for Respected Walter Lewin sir( God of physics)
Mr
Very honest person before solving problems without any hesitation clearly said it is not my solution I have seen several solutions and selected this and changed some concepts to explain more clearly ❤
Thanks professor 😊 for this. I have been waiting for this 🙌
That was a very elegant explanation Professor. In your free body diagram should not another upward force from surface tension be shown ?
You are indeed great sir.
i always thought this was because of surface tension, like the water pulls up the carboard to keep it there. my mind has blown away
Thank you dr walter ❤❤
Tq. Very clear and complete explanation.
Thanks professor please also refer to some advanced questions of IIT JEE it'll help alot
true
Thank you so much Sir for such wonderful videos..
You are really a great teacher❤
❤forthe love phyi...thank you professor
I feel this is an adequate explanation but better for a writing assignment. Where's the math?
I don't understand...In class, at 801x, more than a decade ago, you told us that this would be because of the low static pressure created (in a very thin layer where cup wall touches the card) dude to the higher dynamic pressure, when the water tried to pass. This was the explanation you gave while explaining Total Pressure = Static Pressure + Dynamic Pressure. Just out of curiosity, when did you changed your point of view into this new version ? Why did you give up from the total pressure explanation ?
thanks professor for the Solution :)
Sir your lectures are really helpful for me
Im and advance level student
From Srilanka
Hello sir can you also give ur insight on India's achievement with chandrayan 3 🙏
Sir can you tell in which country do you live presently
GOOD MORNING SIR
Sir, you are the only reason I have started understanding physics and my 10th physics passed because of you.😇😇😇😇😇😇😇
THANK YOU SO MUCH SIR 🤗🤗🤗🤗🤗🤗🤗🤗
Hello, professor I have a question that HOW MANY SIGNIFICANT NUMBERS PRESENT IN 5100 Kg . According to HC Verma there is only 2 significant figures whereas S l Arora says there is 4 significant figures as unit is written so we count all the zeroes. Could you please solve my doubt.
Sir,
Actually I have a question from physics. None of my professors and seniors could solve it. Would you please assist me with it?
The question is:
Derive the expression for the magnitude of magnetic field at a point P in the plane of a current carrying circular loop of radius "a" and the current flowing in the loop is "i" (P is not the center of the circle.)
Sir post Problem 180 as difficult as Problem 179 . Problem 179 was very innovative too.
only 3 people had the correct 3 answers. Problem 179 + solutions took me more than 6 hours work. It was a waste of my time as the problem was too hard.
??? What is the mathematical language of physics called and where can I learn it?
If the cardboard was replaced by an inflexible material would the water then fall?
to be inflexible it would also have to be heavy - yes the water would then fall out
Sir,
Actually I have a question from physics. None of my professors and seniors could solve it. Would you please assist me with it?
The question is:
Derive the expression for the magnitude of magnetic field at a point P in the plane of a current carrying circular loop of radius "a" and the current flowing in the loop is "i" (P is not the center of the circle.)
Sir, please make a video on this if possible, please.
Hello sir i am having a doubt that refractive index of medium is given by sin i /sin t but can't we say it as sin r/ sint is this correct?please tell 🙏
Good morning sir, can you please explain stresses induced in pressure vessels and derivations of equations for these stresses?
I mean for thin cylinders
Longitudinal stress is = p*d/4t,
And circumferential stress= p*d/2t,
But l am having difficulty understanding stresses in thick cylinders, change in dimensions of cylinders due to these stresses, kindly explain
Sir, what does counteracting gravity mean?
And the surface tension thing
Can u explain in simpler terms
I do nor know what cg means - google "surface tension"
Thanks Sir
helped alot i was workin on it thanks
Hello sir, I am a new student in your channel, I just saw one of your videos last night. I am a jee aspirant and My condition is very bad in physics, I need you so much, What shall I do. Please help your student.
you have 2 options
option 1: eat yogurt every day but *never on Fridays*
option 2: Watch all my 94 MIT course lectures. Start with 8.01, then 8.02, then 8.03. Do all the homework and take all my exams. *I guarantee you that you will then do very well on the Physics portion of any freshman college or JEE exam* You will find all information you need on this channel in three playlists "Homework, Exam, SolutionsY & Lecture Notes".
8.01 & 8.02 will each take about 200 hours, 8.03 about 250 hours.
Sir i would like to go on a dinner one day and many more you are best in world 😚❤️❤️💖
Really?I mean can't believe that solution... Is that difference really enough? I have to put numbers and check.. Also why does the why does it fall once it (the cardboard) gets wet
if you wait long enough for the cardboard to get very wet, then the water will fall out - but that's not what the problem was about
I gave exact same explanation just after 5min of posting prblm
Hi l'm your korea fan and l will go mit so can you advice me❤
plz teach again neeet physics plz sir
itz my humble request
Sir I need a financial help From you please help as a humbled people the help is regarding study sir please I am your faithful student SUBHAM BEHERA
Sir im first
First