Physics 14 Finding the Center of Mass (4 of 4) Triangle

[@endorianki]

Agreeing with Cherie, but that's the beauty of a video; you can always just go back and re-watch a particular part you didn't get. After three runthroughs you can come to an understanding. Liked, thanks for making this. =)

[@MichelvanBiezen]

Yes, I am trying to find the middle ground between not going too fast and not going too slow. Thanks for the feedback.

[@ptyptypty3]

this is me talking in 8th grade: "When will I ever need to know this?.. why study it?" this is me after college: " I love my new job as a Mechanical Engineer with General Dynamics!!.. Salary is Super, Benefits fantastic.. a new car..!!"

[@MichelvanBiezen]

Wow, "a new car"? Mike and I still have never owned a new car. I think we're doing something wrong...

[@ptyptypty3]

@@MichelvanBiezen Well.. to be forthright here. I'm 64 years old and I've only had one new car in my life.. lol... the car I drive today is a 2003 Ford Focus and it has only 58,000 miles on it... not too bad!! :) .. and the car I had before that .. was new when I bought it. but I had that for 15 years too.. :) ... New cars become used cars and even a 10 year old car can still drive nicely.. .. Oh and you and Michel are doing just fine.. Cars are for getting from A to B... so are bicycles i guess.. lol... Thanks for your response.. :)

[@sunmo1284]

very helpful! thanks! in class my teacher derived the integral too fast not explaining how to replace the variables into the same ones but you were great

[@MrNoahsamen]

More better then going universities making these easy concept much understandable.

[@kiddogoddo7582]

i was in pinch. I couldnt solve this easy problem and teacher was already marked me F. But i watched this video 2,3 times and i found mistake in teachers lesson. I realized e taught wrong. Thank you very much.

[@GoatzAreEpic]

GOAT

[@jimindecarlo9356]

thanks for making these videos. Theyre very helpful.

[@waqarahmad2428]

center of mass = intral{x dm} /M can we done it at this forula ' your are best .

[@TeenGohan9798]

Are there any videos where u use the center of mass and momentum or impulse to solve a problem?

[@MichelvanBiezen]

What are you solving for?

[@TeenGohan9798]

not sure, i was just wondering because i saw a comment on the momentum problems list, where someone said they used the center of gravity to solve the problem with the 2 bowling balls. I assumed that was a legit, is it not?

[@MichelvanBiezen]

Usually we don't worry about the center of mass with momentum problems. We just assume the forces act through the center of mass.

[@TeenGohan9798]

hmm i see thank u for the clarification :)

[@AllenAK49]

How did you figure out the x-tilda, I don't understand how you got that?

[@MichelvanBiezen]

+AK Wilson Wilson There are lots of videos in the playlist that will show you how: PHYSICS 14 CENTER OF MASS

[@AllenAK49]

+Michel van Biezen OK thank you I'll check them out.

[@ahmedal-ebrashy3691]

One of the most frustrating things is that something so simple van make someone pull their hair fro, frustration. One serious problem I have with this video is that I dont know when to use x telda and y telda? They appear very smart similar. Like I have no idea why cant I use y telda with hirizontal slice or x telda and vice versa? Can you elaborate...thank you very much.

[@hannahchubin1273]

THIS WAS SO HELPFUL THANK YOU!

[@MichelvanBiezen]

Glad it was helpful!

[@draganradosavljevic8982]

Brilliant as always!

[@MichelvanBiezen]

Glad you think so! 🙂

[@anishbhupalam5967]

THANK YOU I LOVE YOU

[@MichelvanBiezen]

Glad you found us.

[@dajaco81]

looking forward to trying this with an irregular hexagon :D

[@MEBMohdSaifuddinKhan]

Is this for a general triangle?

[@MichelvanBiezen]

Yes, this works for any triangle.

[@MEBMohdSaifuddinKhan]

@@MichelvanBiezen But then you used a right angled triangle in the deriviation

[@MichelvanBiezen]

That makes it easier to show the principle. I believe that we made a video that shows an irregular shape.

[@WojMan543]

How would the problem change if there is not uniform mass per unit area?

[@MichelvanBiezen]

Nikolas. Then your mass element (dm) would now become a function of position, like the density may increase linearly with y. For example dm= 3y*(density at y = 0) dV

[@WojMan543]

Michel van Biezen And could this method be translated into three dimensions?

[@eqmalkhair2539]

I can't understand why it dA equal to (1-x)dy and x tilda equal to 1+x divide by 2

[@MichelvanBiezen]

length = x2 - x1 average = (x1 + x2) / 2

[@ishimwecedric2501]

Does anyone see the error on x-tilda? I think it should be equal to (1-x)/2 instead of (1+x)/2 Am I wrong?

[@MichelvanBiezen]

The video is correct.

[@Freakybananayo]

Michel van Biezen how come? Why is it x+1

[@srikarreddy9831]

Nee bonda ra badcow

[@LinkinPark15Ash]

(x+1) because thats how you find the midpoint. If i asked you to find the midpoint between 2 and 4, you'd easily tell that it's 3. the formula to get that is (2+4)/2 = 6/2 = 3

[@atlkurtulmus6993]

1-x is simply width of the segment. (1-x)/2 is how far the midpoint is from both endpoints.so from endpoint (1) its location on the graph would be 1-(1-x)/2. from x it would be x+(1-x)/2 both are equal to (x+1)/2

[@Bwkerbow]

The general formula for center of mass is the sum of the MASSES multiplied by their distances from the point of interest, not area. I feel there really should have been a step included showing how you go from from the general formula to what you threw up there. Great video though, thank you!

[@alvarozerkowski3706]

It was considered that the mass distribution on the triangle was uniform. Therefore, the area is the same as using the mass.

[@brandonkerbow8629]

Alvaro Zerkowski Absolutely I was suggesting that that detail be explicately stated because it may not be immediately obvious to everyone

[@alvarozerkowski3706]

Yes, you are right...

[@dreamaries5244]

he explained it in the previous video

[@brandonkerbow8629]

Ahlam Ghannam Which not everyone has watched. I imagine most people, myself included, don't watch this as a series but rather only arrived at this video after searching for a specific homework problem solution

[@vithunpranesh9920]

how about doin dy=3xdx

[@muhammadhasnain1832]

sir, what is the problem here with the audio of these vedios? plz reply me

[@MichelvanBiezen]

Our old videos were not recorded in stereo. (we had a lot to learn when we started filming.)

[@muhammadhasnain1832]

ok thank you sir,,, bt sir how can i be able to get these vedios with audio record?

[@MichelvanBiezen]

All the new ones have better sound recording. The old one play in mono and can be listened to via a computer.

[@muhammadhasnain1832]

OK THANK YOU VERY MUCH SIR!!!!

[@TomShootsPhoto]

my left ear thanks you for this video!

[@jasonpeng5798]

nobody gives a fuck

[@phoenix-tt]

At first, I was terrified that my headphones broke... Still, the videos are cool

[@Jazzrolls]

I don't understand how he got dA=1-x dy and x tilda = 1+x/2

[@MichelvanBiezen]

If you want to find the midpoint between 4 and 8 you calculate it like this: (4 + 8) / 2 = 6

[@toosikkid123]

Why is x tilde not equal to ((1-x)/2)?

[@Peter_1986]

+toosikkid123 Probably because x-tilde represents the average mass across each small area elements, and thus is equal to the sum of the left and right sides divided by 2. You can compare it with the expression for the average speed of something, which is the sum of the starting and ending speeds divided by 2 (for example, a car that starts from a standstill and accelerates up to 20 mph would have an average speed of (20 + 0) / 2 = 10 mph). I guess that x-tilde works in a similar way here for the centre of mass.

[@mahergad3287]

+laurelindo But I think x-tilde represents the average length not the average mass . Isn't that right ?

[@DrManpreetKSodhi]

X tilde= x+ (1-x)/2=(1+x)/2

[@frenchfryguy2012]

what is the x tilde

[@MichelvanBiezen]

"x tilde" is the center of mass in the x-direction of the small area element. It is something I learned from my professor a very long time ago and it stuck.

[@piecewisetechnologies6607]

very helpful. Thank you very much!

[@amanjain2549]

THANK YOU

[@janayool1001]

in x-axis its 1-x because L=1-x since the base is 1 in y-axis L should be 3-y why you put it as L or you expression L in x-axis = L in y-axis

[@MichelvanBiezen]

Jana, I am not sure what you are asking. (You used the word "it" and I don't know what "it" is).

[@janayool1001]

sorry ..... i mean why Da=(1-x)dy and why Da=(y)dx ?

[@MichelvanBiezen]

Jana, Thanks for clarifying. Da is a small area element in the shape of a rectangle. Thus it has length and width. If the area is oriented vertically, then the width is dx (a small width in the x-direction) and the height is the distance from the bottom of the rectangle to the top of the rectangle. There are a number of examples of this in the calculus playlist.

[@chersw2210]

thank you but its slightly too fast-paced.

[@MrDoa1234]

awesome!

[@amazinglygoodlooking]

Thanks

[@Nemesis-The1]

Hello Michel, great video as always, but I am here to ask for your help with a question... here is the link to how it looks imgur.com/a/tbaoDvd as you can see its not a regular triangle so it makes it difficult for me to figure out the center of mass. I would love if you could shine a little light and brighten the situation for me! the measuring unit is in Millimeters. Thanks in advance!

[@MichelvanBiezen]

Hi Ryan. As it turns out, the center of mass of a triangle (regardless of the shape) is always 1/3 the distance from any base. We are adding it to the list of viewer requests and we'll make a video on it.

[@aadityasharma6855]

Thanku sir

[@swamks69]

tnx!

[@emmagracebeauty01]

Ya I think for the avg joe it was too fast. U went from zero to hundred when u started talking about da and dy. I understood but for some it might be confusing which is why there r more dislikes on this vid. Nonetheless thanks for the vids

[@RaymundoGabriel]

thank you!

[@barsgologlu611]

Shiiiiit

[@alejandromoreira9896]

it should be equal to (1-x)/2 instead of (1+x)/2.

[@MichelvanBiezen]

No, the video is correct.

[@RaymundoGabriel]

thank you!!

[@RaymundoGabriel]

thank you!!

[@RaymundoGabriel]

thank you!