I got 90% for theory work and 100% for practicals in general physics and planning to get at least a 95% in my exam tomorrow. Thank you so much for these videos.
do you never lay awake at night and think oh I still dropped ten percent .to be honest they should have told me,that we regret to inform you that you scored minus ten percent on your lifetime test exam!I might have to sweep floors and scrub toilets for fifty cents an hour! I jest good sir! What a performance,! Imagine if you scored ninety percent with the ladies!you'd be living in Caesar's palace before your nineteenth birthday!ninety percent,? This is a very difficult subject.you didn't, even have the answers in front of you!
2020/7/2 searching for important adds to my E-class project and I feel like I found a treasure in this video.. Thank u veeeeery much mr.matt Anderson best lecture ever 😘👏🏻👏🏻👏🏻👏🏻
حسين علي عبد الجليل كاضم, You're very welcome. Glad you're enjoying the videos. You might also like my new site: www.universityphysics.education Cheers, Dr. A
I have to write an essay about this, and when I looked the three laws of planetary motion elsewhere, it seemed very confusing to me; however, you explained this realllyyy well. Thank you!
New teaching aid called Learning Glass. He's writing normally on the back of a glass pane, the image ricochet's off of a mirror placed diagonally in front of the glass, and then enter's a camera. Without the mirror, everything would appear backwards.
@@carlatteniese2 You can see that his wedding ring is on the hand he isn't writing with, which is traditionally worn on the left hand. He is writing with his right hand, and from his point of view, he is writing normally. There is a mirror between the glass board and the camera, that inverts the video footage.
Idk why but when you talked about helly's comet it really made me enjoy the lesson more because it's so crazy that we might be able to see it in 2061, so crazy! I'm really enjoying this
@@yoprofmatt Hello sir.. The whole video and the concept was crystal clear to me but there is this one part that I didn't understand. 08:55 is the part.. How did we reach to this equation and why did we use V?
@@ishac18120 Since the planet is rotating around the Sun, the planet have a circular motion and a centripetal force is acting on the planet. The magnitude F of the centripetal force is equal to the mass m of the body times its velocity squared v 2 divided by the radius r of its path: F=mv2/r. V is the velocity at which the planet is moving so we use V because their will obviously be a velocity when something moves! Hope this helps! :)
Pls I have 2 questions: 1. If the sun attracts the earth, and the earth attracts the sun, then why do they not collide? 2. Why do we use Kepler's constant for all bodies in our solar system if they do not all move in a circular orbit but the formula for Kepler's constant includes 4π?
Thank you. It makes a lot more sense now.. i am not completely there but getting there, slowly. (Small distraction: How does that "chalkboard" work? Wouldn't it appear backwards on our side?)
The orbits are elliptical because the speed at which the planet's are orbiting the sun prevents them from falling into it , but due to the high speed , they kinda get flung off from the circular orbit and after travelling for a some distance the speed they got after flinging off(idk if am I using the write word here) is lost and the sun's gravity is able to pull them back
Your question regarding the semi-major axis is astute but it turns out that the semi-major axis is the same for a circular or elliptical orbit having the same period. The key is that in an elliptical orbit, one can no longer state that the semi-major axis is equivalent to the radius. It must be defined as 1/2 the length of the entire major axis of the ellipse. Since the Sun does not occupy the center of an elliptical orbit you must shift your perspective away from the circular image provided by Professor Anderson, and envision an ellipse with the Sun at one of its foci. In this case, the Sun’s position has nothing to do with how we measure the semi-major axis.
Professor Anderson has simplified the problem to that of the Earth in a circular orbit around the Sun. This allows for two simplifications. First, the radius r can be assumed to be equal to the semi-major axis. Second, the Sun’s mass far exceeds the Earth so that it can be assumed to be at the center of the circle. There are more general derivations based on the center of mass for both bodies but my attempts to link you to them have been blocked.
Q: When a planet moves a around a star, with different velocities at it’s perihelion and it’s aphelion, does that mean that time on that planet goes slower or faster, because time goes slower when an object moves faster?
Good day! I'd like to ask, Kepler's 3rd Law in valid only in our Solar System or another (solar) systems, too, (most likely) pls ? And how about the g (constant 6,67 x 10^-11) ? Thx
Planetary system is the general term for a group of planets orbiting a parent star. The solar system is the sun's planetary system specifically, since Sol means sun. Kepler's third law is valid in other planetary systems as well, but only among the planets that orbit in that particular planetary system. A hypothetical planet orbiting the sun at 8 AU would have an orbital period of 4 years, which fits Kepler's third law with the planets of the solar system. However, don't expect a planet orbiting a completely different star at the same 8 AU distance to also have an orbital period of 4 years. It is uppercase G that has a value of 6.67e-11 N-m^2/kg^2, and to the best of our knowledge, this is a universal constant. Lowercase g is gravitational field strength, and is specific to an individual world.
I believe that Newton's law of Universal Gravitation was derived from Kepler's laws, so 5:01 you said "Kepler's laws are derivable from Newton's law of gravitation" is somewhat inaccurate. With that being said, I still love your videos!
Kepler's laws are derived from Tycho Brahe's observational data. Newton came up with his law of gravitation to prove Kepler's laws, from the fundamentals of how he believed the mathematics of gravity would work. The multiplication of masses in Newton's law of gravitation is a direct consequence from the empirical observation that force of gravity is proportional to mass, and Newton's third law that gravity like all forces is a two way street. The inverse square part of the law comes from the way a field with no divergence would spread out in space from a spherically symmetric source. Putting these together, we get the M*m/r^2 part of his law of gravity, and the big G is a constant of proportionality to make the units work out. Cavendish's experiment, over a century later, was the first to measure the big G.
He's not actually writing backwards. He uses a mirror between the camera and the transparent board, to film this. Students who see him teach in the flesh, will see the backwards writing on the board. On a screen to the side, they see a live feed of the footage you are seeing, so that the writing is legible.
Im an Indian student, but the way our teachers teach us is like they want us to memorise the things and not understand them. Everyone is in a rat race to remember everything for their exams but nobody clearly understands things. But i have to say american teachers do explain well along with yt indian teachers unlike indian school teachers.
@Abdullah Orilonise It's a lightboard so he either mirrors the video while editing or has some kind of mirror in front of the camera. From his point of view he is writing normally.
Indeed you are correct. We're trying to simplify the physics. Circular orbit is an ellipse of ellipticity = 1. We approximate this to make sense with Newton's laws for circular motion. Since Earth is in a near circular orbit, it works great. Cheers, Dr. A
G MAN, Can you explain a bit more what you mean by that? There are, of course, "flaws" in Kepler's Laws that are only fully explained by general relativity, but it sort of depends on what you call "major." Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A
how would I solve this question: if Kepler's constant for a STAR is 6.00x10^-12 s^2/m^3, what would the mass of the planet be in scientific notation? I've been struggling about it for a while, and can't find a way to isolate mass in the equation with no info on the Period or the Radius: Ta^2/Ra^3=Tb^2/Rb^3. Thank you...
![“อ.เบียร์ คนตื่นธรรม” มาตามคำเรียกร้อง แหกศาสตร์ฮวงจุ้ย เตือนสติอย่างมงาย | แฉ 7 พ.ย. 67 [1/3]](http://i.ytimg.com/vi/5fc4S3xBNfc/mqdefault.jpg)
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You still helping people after 8 YEARS nice video you explained everything soo good thank you so much!!!
That's the great thing about video. I never go gray.
Cheers,
Dr. A
I got 90% for theory work and 100% for practicals in general physics and planning to get at least a 95% in my exam tomorrow. Thank you so much for these videos.
do you never lay awake at night and think oh I still dropped ten percent .to be honest they should have told me,that we regret to inform you that you scored minus ten percent on your lifetime test exam!I might have to sweep floors and scrub toilets for fifty cents an hour! I jest good sir! What a performance,! Imagine if you scored ninety percent with the ladies!you'd be living in Caesar's palace before your nineteenth birthday!ninety percent,? This is a very difficult subject.you didn't, even have the answers in front of you!
I need help
You are my favorite physics teacher
Wow, great to hear. Thanks for the comment.
Cheers,
Dr. A
Matt Anderson
Thank you so much
Honestly I wish one day
I will get master degree with you sir
Sounds promising.
Cheers,
Dr. A
i fully agree
YEAH DUDE ME ALSO
After a decade...it is still the most useful explanation...thanks a lot...you make physics interesting
still helping GREATLY after 6 years!
I’m middle-aged and taking Life in the Universe. Thank you for this video. It helps me visualize Kepler’s Laws!🙌🏿
2020/7/2 searching for important adds to my E-class project and I feel like I found a treasure in this video.. Thank u veeeeery much mr.matt Anderson best lecture ever 😘👏🏻👏🏻👏🏻👏🏻
حسين علي عبد الجليل كاضم,
You're very welcome. Glad you're enjoying the videos.
You might also like my new site: www.universityphysics.education
Cheers,
Dr. A
I have to write an essay about this, and when I looked the three laws of planetary motion elsewhere, it seemed very confusing to me; however, you explained this realllyyy well. Thank you!
Crystal clear explanation - Great thanks Prof Matt Anderson
thanks for your help professor, im working on tomorrows exam and this video really helped, greetings from turkey.
Your explanations are so smooth!
Animesh,
Great comment, thanks.
You might also like my new website: www.universityphysics.education
Cheers,
Dr. A
Who else is confused about how he is writing backwards perfectly or is it only me ....
Yeah, this drives me crazy too--and I can write backward and upside down.
Actually, he is doing what we all do; he is writing left to right behind a piece of glass. He happens to be left-handed.
New teaching aid called Learning Glass. He's writing normally on the back of a glass pane, the image ricochet's off of a mirror placed diagonally in front of the glass, and then enter's a camera. Without the mirror, everything would appear backwards.
@@carlatteniese2 You can see that his wedding ring is on the hand he isn't writing with, which is traditionally worn on the left hand. He is writing with his right hand, and from his point of view, he is writing normally. There is a mirror between the glass board and the camera, that inverts the video footage.
The video stream could also be digitally reversed before display.
Idk why but when you talked about helly's comet it really made me enjoy the lesson more because it's so crazy that we might be able to see it in 2061, so crazy! I'm really enjoying this
I am so thankful for your great lectures. Was very helpful even after 9 years love from India.
So grateful, cant thank you enough. I wish was thought this way in Secondary school days.
You are great sir
Love and respect from Nepal 🇳🇵 🇳🇵
kundan Poudel,
Thanks for the comment, and keep up with the physics!
You might also like my new website: www.universityphysics.education
Cheers,
Dr. A
you are the best !!!! perfect explanation
thank you Dr.
Ha a,
You're very welcome. Glad you're enjoying the videos.
You might also like my new site: www.universityphysics.education
Cheers,
Dr. A
Sir you are a very good physics teacher
this is extremely helpful... for students post covid
Glad to hear it.
Cheers,
Dr. A
That's awesome you lecture behind a smart glass with a bright font
You just make this subject very easy and interesting. Thanks
Thanks for the shout out!
Cheers,
Dr. A
Your the best physics teacher
My 1st year engineering lecturer made me hate physics, you have restored my love for physics
Terrific explanation Sir,
I wish you were my physics teacher
Thanks. I'll just try to be everyone's physics teacher here on TH-cam.
Cheers,
Dr. A
Sir u r amazing but we need deep and deeper explanations and examples of theroms thank u sir yous obediently student
Thanks for the comment. We're working on new stuff.
Cheers,
Dr. A
@@yoprofmatt Hello sir.. The whole video and the concept was crystal clear to me but there is this one part that I didn't understand. 08:55 is the part.. How did we reach to this equation and why did we use V?
@@ishac18120 Since the planet is rotating around the Sun, the planet have a circular motion and a centripetal force is acting on the planet. The magnitude F of the centripetal force is equal to the mass m of the body times its velocity squared v 2 divided by the radius r of its path: F=mv2/r.
V is the velocity at which the planet is moving so we use V because their will obviously be a velocity when something moves!
Hope this helps! :)
Pls I have 2 questions:
1. If the sun attracts the earth, and the earth attracts the sun, then why do they not collide?
2. Why do we use Kepler's constant for all bodies in our solar system if they do not all move in a circular orbit but the formula for Kepler's constant includes 4π?
All my respect to you sir from Egypt
Hello to my Fandersons™ in Egypt! Thanks for tuning in.
Cheers,
Dr. A
You are the best teacher. You change my thoughts . Thank you
M 07,
You're very welcome. Glad you're enjoying the videos.
You might also like my new site: www.universityphysics.education
Cheers,
Dr. A
sir, you're amazing
thanks
Thanks for watching!
Cheers,
Dr. A
This is really helping me for my 10th grade
For the first time I can understand this stuff. Thanks Prof. Anderson !
Am I the only one who thinks you look like doctor Strange without facial hair!?
YES! I thought the same thing too.
No he don't
@@xixizang2798 haha...give him a red cloak.
@@lordlwando wow I wrote that comment in my 11th grade...now I'm in a university.
Unbelievable sir Namaste🙏 from India🇮🇳
Thank you very much.
I am your fan + student from Oregon.
best teacher
Love u sir tq so much this helped me literally best teacher 😄😄😄😄😃😃😃😃😃😃😃😃😃😃😊😊😊😊😊
You are very welcome.
Cheers,
Dr. A
Very notch way of teaching
Thank you. It makes a lot more sense now.. i am not completely there but getting there, slowly. (Small distraction: How does that "chalkboard" work? Wouldn't it appear backwards on our side?)
Lol I want to know the same thing
I think it's just video itself mirrored vertically!!
I'm probably not going to make Halley's next appearance, so that's kind of a bummer
Please solve multiple choice questions related topic
i am only 13 but i thought that is video was very easy to understand thanks :)
Wonderful sir love from India
I love Ur teaching
Cheers for Dr. A thanks Sir for the great explanation
Pralay Pati,
You're very welcome. Glad you're enjoying the videos.
You might also like my new site: www.universityphysics.education
Cheers,
Dr. A
Thanks sir
Which Technique is used to write on transparent board.
Equal areas in equal times is a bit imprecise! It's true only if the origin of the revolving positional vector is the Sun, not the second focus.
Professor but what is the reason for eleptical orbits?
the question is...Why not??
The orbits are elliptical because the speed at which the planet's are orbiting the sun prevents them from falling into it , but due to the high speed , they kinda get flung off from the circular orbit and after travelling for a some distance the speed they got after flinging off(idk if am I using the write word here) is lost and the sun's gravity is able to pull them back
thanks for great lecture. But you just show Kepler third law for circular orbit. How it extended for elliptical orbit
Finally I understand Kepler's laws
Great to hear! Now grab your telescope and head to the hills.
Cheers,
Dr. A
Matt Anderson I wish I could do that😓
sir do you write with left hand and flipped texts ?
I was also wondering how its done. Wether he has backwards whiting skills or if there are clever camera tricks @ play.
awesome explanation an osm trick
Your explanation is so simple😍❤..but i can't understand how radius can be same as semi major axes for elliptical orbits..
Your question regarding the semi-major axis is astute but it turns out that the semi-major axis is the same for a circular or elliptical orbit having the same period. The key is that in an elliptical orbit, one can no longer state that the semi-major axis is equivalent to the radius. It must be defined as 1/2 the length of the entire major axis of the ellipse. Since the Sun does not occupy the center of an elliptical orbit you must shift your perspective away from the circular image provided by Professor Anderson, and envision an ellipse with the Sun at one of its foci. In this case, the Sun’s position has nothing to do with how we measure the semi-major axis.
Professor Anderson has simplified the problem to that of the Earth in a circular orbit around the Sun. This allows for two simplifications. First, the radius r can be assumed to be equal to the semi-major axis. Second, the Sun’s mass far exceeds the Earth so that it can be assumed to be at the center of the circle. There are more general derivations based on the center of mass for both bodies but my attempts to link you to them have been blocked.
Really cool video, thanks a lot!
You're very welcome. Keep up with the physics!
Cheers,
Dr. A
More than class ..iam thinking about how they shoot .like wr is camera direction.....
Why do I feel like you are writing the letters backwards and doing it perfectly? 🤯
I think he writes it regularly (from his perspective), and then inverts the video.
@@m1000-n8w Could this be real or is it just your point of view?
Q: When a planet moves a around a star, with different velocities at it’s perihelion and it’s aphelion,
does that mean that time on that planet goes slower or faster,
because time goes slower when an object moves faster?
thank u very mach for the explanation.....that was awesome...thank u.....
Good day! I'd like to ask, Kepler's 3rd Law in valid only in our Solar System or another (solar) systems, too, (most likely) pls ? And how about the g (constant 6,67 x 10^-11) ? Thx
Planetary system is the general term for a group of planets orbiting a parent star. The solar system is the sun's planetary system specifically, since Sol means sun.
Kepler's third law is valid in other planetary systems as well, but only among the planets that orbit in that particular planetary system. A hypothetical planet orbiting the sun at 8 AU would have an orbital period of 4 years, which fits Kepler's third law with the planets of the solar system. However, don't expect a planet orbiting a completely different star at the same 8 AU distance to also have an orbital period of 4 years.
It is uppercase G that has a value of 6.67e-11 N-m^2/kg^2, and to the best of our knowledge, this is a universal constant. Lowercase g is gravitational field strength, and is specific to an individual world.
well explained. thank you.
thats a cool looking board
Sir what kind of device did you use to write on
please tell me sir 🤔🤔🤔
learning.glass
Thanku very much sir 😊😊☺.
Tanya Shreee,
You're very welcome. Glad you're enjoying the videos.
You might also like my new site: www.universityphysics.education
Cheers,
Dr. A
@@yoprofmatt 🙂🙂
@@yoprofmatt 🙂🙂
lovely story about the comet
Sir i dont understand the part where 10:53 T² = 4pie² by GMs r³ turns to T² proportional r³ ? I hope you do have the time answer my question.. , sir.
Guys, how is his inverted writing so perfect?
How the sun"s mass was calculated.
(I understand that mass of earth could be calculated by considering "average" specific mass on earth.)
I believe that Newton's law of Universal Gravitation was derived from Kepler's laws, so 5:01 you said "Kepler's laws are derivable from Newton's law of gravitation" is somewhat inaccurate. With that being said, I still love your videos!
Kepler's laws are derived from Tycho Brahe's observational data. Newton came up with his law of gravitation to prove Kepler's laws, from the fundamentals of how he believed the mathematics of gravity would work.
The multiplication of masses in Newton's law of gravitation is a direct consequence from the empirical observation that force of gravity is proportional to mass, and Newton's third law that gravity like all forces is a two way street. The inverse square part of the law comes from the way a field with no divergence would spread out in space from a spherically symmetric source. Putting these together, we get the M*m/r^2 part of his law of gravity, and the big G is a constant of proportionality to make the units work out. Cavendish's experiment, over a century later, was the first to measure the big G.
Excellent explanation sir
Thank you. Glad to be of help.
Cheers,
Dr. A
Top notch explanation
Thanks much.
Cheers,
Dr. A
Thanks Matt
Paul Crooks,
You're very welcome. Glad you're enjoying the videos.
You might also like my new site: www.universityphysics.education
Cheers,
Dr. A
Thank you so much sir!
Sir...how can I practice mirror writing like you
He's not actually writing backwards. He uses a mirror between the camera and the transparent board, to film this.
Students who see him teach in the flesh, will see the backwards writing on the board. On a screen to the side, they see a live feed of the footage you are seeing, so that the writing is legible.
@@carultch Thank you
Where he is writing.any body knows please explain....
Im an Indian student, but the way our teachers teach us is like they want us to memorise the things and not understand them. Everyone is in a rat race to remember everything for their exams but nobody clearly understands things. But i have to say american teachers do explain well along with yt indian teachers unlike indian school teachers.
how does he write in the board? Does he write backwards ? Or is it a mirror trick?
Ban Nana I’m pretty sure this is a mirror trick.
Can someone explain why the sum of the forces add up to Sum(F)=(Mp*V^2)/r ??? Thanks
centripital acceleration = v^2/r
accordng to 2nd law of newton f=ma
hence centripital force=mv^2/r
How log does it take to write like that and do it like it was normal Jesus Christ you have m full respect
The video is mirrored
He write in reverse or there is kinda edit
@Abdullah Orilonise It's a lightboard so he either mirrors the video while editing or has some kind of mirror in front of the camera. From his point of view he is writing normally.
شكرا.
Why derivation for circular orbits when we know that orbits motion is elliptical m???
Indeed you are correct. We're trying to simplify the physics. Circular orbit is an ellipse of ellipticity = 1. We approximate this to make sense with Newton's laws for circular motion. Since Earth is in a near circular orbit, it works great.
Cheers,
Dr. A
Fantastic
Wait…… I was watching and thinking…and then I realized… ISN’T THIS GUY WRITING MIRRORED TO US???
I've actually heard there was a major flaw in keplers laws tho is that true
G MAN,
Can you explain a bit more what you mean by that? There are, of course, "flaws" in Kepler's Laws that are only fully explained by general relativity, but it sort of depends on what you call "major."
Thanks for the comment, and keep up with the physics!
You might also like my new website: www.universityphysics.education
Cheers,
Dr. A
Why has no one commented on the fact this guy is writing backwards
Nice editing
Thanks, but not sure we had much editing on this one.
Cheers,
Dr. A
Thank youuuuuuuu
Hi, how do write flipped?😅
www.learning.glass
Cheers,
Dr. A
Matt Anderson... remember the name👊
An great sir (he can write left
How could you write backwards ?
GENDAI UI,
Not writing backwards (I'm not that talented). The board is called Learning Glass. You can check it out at www.learning.glass
Cheers,
Dr. A
How you write
I wanna be in his class
I wish u are my teacher
how would I solve this question:
if Kepler's constant for a STAR is 6.00x10^-12 s^2/m^3, what would the mass of the planet be in scientific notation?
I've been struggling about it for a while, and can't find a way to isolate mass in the equation with no info on the Period or the Radius: Ta^2/Ra^3=Tb^2/Rb^3.
Thank you...
@5:30 eccentricity of 0
I like your . Marker
Thank you, I like it too.
Cheers,
Dr. A
♥
Science Tube,
Thanks for the comment, and keep up with the physics!
You might also like my new website: www.universityphysics.education
Cheers,
Dr. A
Matt Anderson Professor, fallen in love with your teaching, the lectures are engrossing.
Thanks for the website link.
The Sun is moving, not at a focus.
Poggers
What the hell you are writing with ?