There's also a Mr. Anderson for AP Environmental Science wtf Maybe all the Mr. Andersons have a talent for teaching, unlike the teachers I have at school it seems
sometimes it's not about the professor,,, it's very unfortunate when we have a very talkative seatmate. Even in the middle of discussions it keeps on talking until we get distracted from the discussion.
In the name of God most mirceful and most beneficiant God gives All universals facilities food's and Waters money banks owners and cash House's churches masjeds imams bargas mandars bardvaras girls and boys beautifuls 😍❤️ inttigents healthys strong's friends and fans gives spurrats of always gives ends of universe's life's long's inifinities babies twins beautifuls 😍❤️ inttigents healthys strong's gives All universals Religion's boys beautifuls 🤩❤️ inttigents healthys strong's gives All universals facilities Brand's car's Motor bikes clothes mobile's phone and Links All universals girls friends and fans beautiful 😍❤️ inttigent healthy strong friends and fans always gives happy
SURYAKANT GAIKWAD, You're very welcome. Glad you're enjoying the videos. You might also like my new site: www.universityphysics.education Cheers, Dr. A
Juuuuuuuuuuuuuu-sssss. Belo. Pricisly at the point, of squaring. Belo was put to rest, amd there was no squaring. Infortunatly. And the same goes for his other buddies, at the East, amd the South gate. The departed will be remembered².
This is great video. i think inertia moment would be much easier to understand if you did make at least one more example of how to calculate moment of inertia, for example of a cube . thanks
The easiest examples are examples with circular symmetry, as you can split them in to shapes with a known moment of inertia from first principles. For instance, consider a solid cylinder. of length L and radius R To make it interesting, suppose its density has cylindrical symmetry, but is not uniform. Suppose its density at distance r from the axis is given by rho(r) = J - K*r, where J and K are constants. Start by considering a mass element that is a thin hollow cylinder of thickness dr at position r from its center. The volume of this mass element is 2*pi*r*L*dr. The mass of each infinitesimal mass element is therefore dm = 2*pi*L*rho(r)*r*dr. We can find the total mass by integrating: m = int 2*pi*L*rho(r)*r*dr We are also interested in integrating r^2*dm from r=0 to R. I = int 2*pi*L*rho(r)*r*r^2*dr I'll leave the rest of the steps to you. At the end of the calculation, you'll get: m = pi*L/3 * (3*J - 2*K*R)*R^2 I = pi*L/10 * (R^4 (5*J - 4*K*R)) In terms of total mass: I = 3/10*m*R^2 * (5*J - 4*K*R)/(3*J - 2*K*R) When K = 0, which would mean density is uniform, instead of linearly varying with r, this reduces to: I = 1/2*m*R^2, which is the formula to use for a solid uniform cylinder.
bbasit, Yep, you've got to do a (potentially complicated) integral. Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A
It's the rotational equivalent to the m in Newton's second law. It is a property that depends on mass, shape, distribution of mass, and axis of rotation, which quantifies how difficult it is to give a rigid body an angular acceleration.
He plays a live-feed on a monitor to his side, so that the students who see him teaching in the flesh, can see the mirrored footage live, and read his handwriting normally. This means that he has to plan in advance to use his left hand to demonstrate the right-hand rule, so that his mirrored footage shows a right hand demonstrating it.
Because there are two factors that make it contribute twice to the equation. Factor 1: Because it is a rigid body, each point on the body has to complete a circumference in the same period of rotation. This means that the linear velocity is proportional to the radial position from the axis of rotation. Factor 2: Angular momentum is r cross linear momentum. The angular momentum of a point mass is proportional to its position from the axis of rotation. The two factors combine to become a squaring of the r in the integral that calculates moment of inertia in general. This means that for most circular objects, you'll see that moment of inertia is equal to k*M*R^2, where k is a factor that depends on shape, M is the total mass, and R is the radius of the object.
why we multiply the mass of the particle by the square radius of rotation when we calculate the moment of inertia? why it is not without that square ? and is it wrong(or why it is wrong) if we said that moment of inertia= mass of the object multiplyed by square destance from the center of gravity of that object ?
Areli, Pacing is important. Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A
legendary lectures....but i have a big question which i did not get any reply from anyone ,i too dont have any idea .what is meant by moment and moment of inertia.
It can be relaTed to pressur e as area increases pressure decreases for the whole system the same for MOI as mass is more and more distributed over a large surface it becomes less effective
The term moment (in general) means quantity multiplied by distance from an origin. This is why torque is called "moment of a force", and why dipole moments get their name. Same with moments of inertia. It really is a second moment of mass, because the radius is squared, but we call it moment of inertia or rotational inertia. What moment of inertia means, is an effective property of how the mass of a rotating body is distributed, to form an analogous property to mass when writing the angular equivalent of Newton's second law. Instead of the linear F_net=m*a, moment of inertia is used for the angular tau_net = I*alpha, that is analogous to Fnet=m*a. There is an analogous quantity in structural analysis called "second moment of area" that is calculated in a similar manner, and often called "area moment of inertia" as a misnomer. It has nothing to do with inertia, because it really is the integral of each infinitesimal area element times r^2, rather than each mass element.
Chi Bey, Knight, "Principles of Physics" Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A
You're right that in general, r does not need to be constant. However, for the wheel at 5:39, r is constant since the wheel has a fixed radius. Cheers, Dr. A
I have watched a whole lot of videos on this subject and this is the best. Where mr2 comes from, it is from kinetic energy formula, E=1/2mv2, where v=rw , it was nice if Dr. Anderson had included this in his video.
transformer889, Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A
hello sir, thank you for such a great video. I have question that does the rapid change in cross section would affect the n second moment of area near the area where rapid changes occur? thanks in advanced. waiting for ur positive response
When did Benedict Cumberbatch take a physics class?
Cumberbatch can do anything!
Cheers,
Dr. A
how the fuck does that look like Battlefield Counterstrike?
My dog won't let me watch this video. The pen in the video is making a squeaking noise that's driving my dog crazy!!!
Or perhaps your dog already understands physics!
Cheers,
Dr. A
@@yoprofmatt holy cow
Its driving me crazy.
Good job! But how to make this kind of video, that's interesting..
All you need is a camera, glass, and a marker. Then use software to flip the video horizontally.
There's also a Mr. Anderson for AP Environmental Science wtf
Maybe all the Mr. Andersons have a talent for teaching, unlike the teachers I have at school it seems
Thank You very much for this video sir and you look like Dr. Strange ;>)
Also McGyver (original version) with a new haircut :)
DUDE THE PEN SQUEAKING DX
Antoinette,
Pen squeak is truly awful. We are fixing the audio on my new website: www.universityphysics.education
Cheers,
Dr. A
Your lectures are awesome sir..love from India
Much love back to India.
Cheers,
Dr. A
I really wish you would be my physics professor at college. I like the way you explain every topic.
Fahim,
Well there's a sure cure for that. Come to San Diego State University!
Cheers,
Dr. A
Haha..It would be great prof. Anderson.
By the way, thank you so much for your respond.
sometimes it's not about the professor,,, it's very unfortunate when we have a very talkative seatmate. Even in the middle of discussions it keeps on talking until we get distracted from the discussion.
Sir Anderson , It's a pleasure to watch your courses ; greeting from an engineer in a cargo ship
Thanks for letting me know where you're watching these. That's awesome. Be safe.
Cheers,
Dr .A
@@yoprofmatt In the example with the wheel of mass M, is the shape a solid disc (i.e. mass throughout the whole circle) or a hollow ring?
He reminds of the MC from prison break.
This so well explained and in a very simple way!Thank you very much for making this video,it helped me a lot😊!
I am not clear why this genius professor of physics has only 95.1k subscribers
He just got one more subscriber
In the name of God most mirceful and most beneficiant God gives All universals facilities food's and Waters money banks owners and cash House's churches masjeds imams bargas mandars bardvaras girls and boys beautifuls 😍❤️ inttigents healthys strong's friends and fans gives spurrats of always gives ends of universe's life's long's inifinities babies twins beautifuls 😍❤️ inttigents healthys strong's gives All universals Religion's boys beautifuls 🤩❤️ inttigents healthys strong's gives All universals facilities Brand's car's Motor bikes clothes mobile's phone and Links All universals girls friends and fans beautiful 😍❤️ inttigent healthy strong friends and fans always gives happy
My concepts is clear now . Thx professor 👍😊
SURYAKANT GAIKWAD,
You're very welcome. Glad you're enjoying the videos.
You might also like my new site: www.universityphysics.education
Cheers,
Dr. A
Everyone's talking abt the pen squek but no one is talking abt the fact that he's writing -backwards- sdrawkcab..
Juuuuuuuuuuuuuu-sssss. Belo. Pricisly at the point, of squaring. Belo was put to rest, amd there was no squaring. Infortunatly. And the same goes for his other buddies, at the East, amd the South gate. The departed will be remembered².
Wish i had a teacher like you...thank you so much for your videos its really helpful....
Thank god someone explained how to get those constants in front of MR²
Sir...u made me understand this very clearly...thank u sooo much!!
Wow! 7yrs ago...
And this video is still helpful. Thanks 😊
Glad it was helpful!
Cheers,
Dr. A
My cat likes this professor. Apparently, the squeaky sounds of his pen sound like birds to her :D
Bruh is defying the Laws of Physics by writing on air and expecting us to not be able to tell. We are not that stupid sir.
GREAT VIDEOS...……..Your spatial skills are off the charts writing backwards like that
JBSC,
Thanks for the comment, and keep up with the physics!
You might also like my new website: www.universityphysics.education
Cheers,
Dr. A
Hernandez Barbara Thompson Kenneth Taylor Helen
Really helps me at school.....thanks
Did anyone else see the glitch at 1:45? The simulation is deteriorating. We are witnessing here the great collapse ppl
This is great video. i think inertia moment would be much easier to understand if you did make at least one more example of how to calculate moment of inertia, for example of a cube . thanks
The easiest examples are examples with circular symmetry, as you can split them in to shapes with a known moment of inertia from first principles.
For instance, consider a solid cylinder. of length L and radius R To make it interesting, suppose its density has cylindrical symmetry, but is not uniform. Suppose its density at distance r from the axis is given by rho(r) = J - K*r, where J and K are constants.
Start by considering a mass element that is a thin hollow cylinder of thickness dr at position r from its center. The volume of this mass element is 2*pi*r*L*dr. The mass of each infinitesimal mass element is therefore dm = 2*pi*L*rho(r)*r*dr.
We can find the total mass by integrating:
m = int 2*pi*L*rho(r)*r*dr
We are also interested in integrating r^2*dm from r=0 to R.
I = int 2*pi*L*rho(r)*r*r^2*dr
I'll leave the rest of the steps to you. At the end of the calculation, you'll get:
m = pi*L/3 * (3*J - 2*K*R)*R^2
I = pi*L/10 * (R^4 (5*J - 4*K*R))
In terms of total mass:
I = 3/10*m*R^2 * (5*J - 4*K*R)/(3*J - 2*K*R)
When K = 0, which would mean density is uniform, instead of linearly varying with r, this reduces to:
I = 1/2*m*R^2, which is the formula to use for a solid uniform cylinder.
man you looks like bennedikt cumberbatch i swear
Does this man really write backwards? hehe xD
Thanks for explaining
Wow.. it was helpful.. thnku so much sir
Biju Joseph,
You're very welcome. Glad you're enjoying the videos.
You might also like my new site: www.universityphysics.education
Cheers,
Dr. A
Sir Anderson,how can we calculate moment of inertia for a frustum as its shape is not uniform
for any non-uniform shape you need to just do the integral !, you can also divide it into multiple geometries to ease the solution ! ..
bbasit,
Yep, you've got to do a (potentially complicated) integral.
Thanks for the comment, and keep up with the physics!
You might also like my new website: www.universityphysics.education
Cheers,
Dr. A
Single Mass I like it ❤
YES SIR, SALUTE
I learned a ton from this video. I still don't understand what moment of inertia actually is.
Classic. This happens when mathematicians explain physics or when physicists believe that physics is primarily about maths.
It's the rotational equivalent to the m in Newton's second law. It is a property that depends on mass, shape, distribution of mass, and axis of rotation, which quantifies how difficult it is to give a rigid body an angular acceleration.
the poor students have to decode all the backwards handwriting
He plays a live-feed on a monitor to his side, so that the students who see him teaching in the flesh, can see the mirrored footage live, and read his handwriting normally.
This means that he has to plan in advance to use his left hand to demonstrate the right-hand rule, so that his mirrored footage shows a right hand demonstrating it.
Thank you for explaining. My test is tomorrow and I did not have any information to understand, but thank you for clarifying some points for me.
Thanks bro ❤
Love your videos
Love from India sir❤️
Excellent 👌👍
Ten points to Ravenclaw for backward writing
Why do we SQUARE the r?
Because there are two factors that make it contribute twice to the equation.
Factor 1:
Because it is a rigid body, each point on the body has to complete a circumference in the same period of rotation. This means that the linear velocity is proportional to the radial position from the axis of rotation.
Factor 2:
Angular momentum is r cross linear momentum. The angular momentum of a point mass is proportional to its position from the axis of rotation.
The two factors combine to become a squaring of the r in the integral that calculates moment of inertia in general. This means that for most circular objects, you'll see that moment of inertia is equal to k*M*R^2, where k is a factor that depends on shape, M is the total mass, and R is the radius of the object.
why we multiply the mass of the particle by the square radius of rotation when we calculate the moment of inertia? why it is not without that square ? and is it wrong(or why it is wrong) if we said that moment of inertia= mass of the object multiplyed by square destance from the center of gravity of that object ?
Look up dimensional analysis, proportionality and take some calc II or III, that should be able to answer your question
Yes 🖐️
Thanks so much for making this topic understandable.
Nice sir keep going love from srilanka...❤
Regards from an Indian student..... This is soooo simple 💯🔥
Thanks doctor I want to communicate with you
Dr.s.murphy dad
Like the good doctor?
Cheers,
Dr. A
Does no one realize he is writing everything backwards?
Tried that. Too hard.
th-cam.com/video/CWHMtSNKxYA/w-d-xo.html
Cheers,
Dr. A
No, they mirror the video
Love from india I love physics
love it
Not the usual reaction to moment of inertia, but I'll take it.
Cheers,
Dr. A
I wish my physics professor would go at this pace...
Areli,
Pacing is important.
Thanks for the comment, and keep up with the physics!
You might also like my new website: www.universityphysics.education
Cheers,
Dr. A
Thank you so much sir, I really appreciate you for your cooperation.👍👍👍👍
It's my pleasure.
Cheers,
Dr. A
thank you soo much, everything is clear now
Which is what we call ''' dm ''
Yep, dm is an infinitesimal mass element. Integrate over all the mass with each appropriate r^2 and you've got it.
Cheers,
Dr. A
@@yoprofmatt thank you for everything ❤️
legendary lectures....but i have a big question which i did not get any reply from anyone ,i too dont have any idea .what is meant by moment and moment of inertia.
Effective mass
It can be relaTed to pressur e as area increases pressure decreases for the whole system the same for MOI as mass is more and more distributed over a large surface it becomes less effective
The term moment (in general) means quantity multiplied by distance from an origin. This is why torque is called "moment of a force", and why dipole moments get their name. Same with moments of inertia. It really is a second moment of mass, because the radius is squared, but we call it moment of inertia or rotational inertia.
What moment of inertia means, is an effective property of how the mass of a rotating body is distributed, to form an analogous property to mass when writing the angular equivalent of Newton's second law. Instead of the linear F_net=m*a, moment of inertia is used for the angular tau_net = I*alpha, that is analogous to Fnet=m*a.
There is an analogous quantity in structural analysis called "second moment of area" that is calculated in a similar manner, and often called "area moment of inertia" as a misnomer. It has nothing to do with inertia, because it really is the integral of each infinitesimal area element times r^2, rather than each mass element.
Love from South Korea
What is the book that you are referring to
Chi Bey,
Knight, "Principles of Physics"
Thanks for the comment, and keep up with the physics!
You might also like my new website: www.universityphysics.education
Cheers,
Dr. A
SQUEAK
5:21
But the r isn't constant
Why is it made a constant?
You're right that in general, r does not need to be constant. However, for the wheel at 5:39, r is constant since the wheel has a fixed radius.
Cheers,
Dr. A
Love from India
Aryavat Era,
Love back to India!
You might also like my new website: www.universityphysics.education
Cheers,
Dr. A
Wow .. you are Amazing..
Thank you. I'm sure you're amazing too.
Cheers,
Dr. A
the squeaky marker
Brutal, isn't it? Got better ones now.
Cheers,
Dr. A
I have watched a whole lot of videos on this subject and this is the best. Where mr2 comes from, it is from kinetic energy formula, E=1/2mv2, where v=rw , it was nice if Dr. Anderson had included this in his video.
transformer889,
Thanks for the comment, and keep up with the physics!
You might also like my new website: www.universityphysics.education
Cheers,
Dr. A
Fine explications, Profesor. Excelent. Please continue with with your classes
hello sir, thank you for such a great video. I have question that does the rapid change in cross section would affect the n second moment of area near the area where rapid changes occur? thanks in advanced. waiting for ur positive response
yes
Can you tell me the relationship ?