Centroid of a Composite Shape - Tabular Method - Part 1

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  • čas přidán 30. 01. 2017
  • This is part 1 of 2 of a video to explain how to calculate the centroid (center of area) of a section.
    Part 2 available from the following link
    • Centroid of a Composit...

Komentáře • 86

  • @govindcharan7827
    @govindcharan7827 Před 6 lety +1

    Very nice explaination . Loved it

  • @nadia675123964523965
    @nadia675123964523965 Před 3 lety +5

    just gets straight to the fking point, excellent video has helped me greatly! keep up the good work

  • @mr.unknown9675
    @mr.unknown9675 Před 5 lety +2

    sir, this is very helpful and plz make more videos on this topic

  • @siteramodel7414
    @siteramodel7414 Před 5 lety

    nice MR HELPED ME A LOT GOOD EXPLANATIONS THUMBS UPPPP

  • @moseskadungure7370
    @moseskadungure7370 Před 5 lety +2

    nice explanation indeed

  • @derrickvincent612
    @derrickvincent612 Před 5 lety

    Great explanation

  • @allfiredupltd9108
    @allfiredupltd9108 Před 3 lety +2

    Thank you so much finally after trolling through CZcams I have found somebody able to explain this to me

  • @sukhpreetsingh3844
    @sukhpreetsingh3844 Před 4 lety +1

    sir this is really helpful for me thanks

  • @k4x4map46
    @k4x4map46 Před 5 lety

    Great stuff thanks...

  • @mohamedmenasy2253
    @mohamedmenasy2253 Před 4 lety

    Very useful

  • @AntoMatc97
    @AntoMatc97 Před 7 lety

    good explanation

  • @swethaninetshitwarini9017

    Please do more videos of this topic 🙏

  • @eliemutia4620
    @eliemutia4620 Před 3 lety +1

    thank youuuuuuu

  • @okeniranolumide3663
    @okeniranolumide3663 Před 4 lety +4

    pls sir. to calculate for bar x of a triangle what we use is 0ne-third of the base but now u are using two-third... i dont get sir

    • @corneliskok7794
      @corneliskok7794  Před 4 lety

      this is quite difficult to explain in words so I'll show a picture :-)
      en.wikipedia.org/wiki/Centroid#/media/File:Triangle_centroid_2.svg
      The idea is that the centroid is one third of the distance from the right side of this image, and 2/3 of the distance from the left side.
      You will notice that, when compared with a square, the triangle has a right part with more area, and a left part with less area. The centroid should be closer to the side with the more area. ie. the centroid should be closer to the right side.
      (grammatical errors are intentional in the sentence above as I think this makes it easier to understand)

    • @corneliskok7794
      @corneliskok7794  Před 4 lety

      Oh, by the way, sir is reserved for knights and people that would be eligible to be added to this list:
      en.wikipedia.org/wiki/List_of_honorary_British_knights_and_dames
      I haven't got that right yet so Cornelis will do, for now :-P

    • @mason4634
      @mason4634 Před 3 lety

      You most likely don't need this input anymore but you can also just do 8 x 1/3 and then subtract the product of 8 x 1/3 by 8.

  • @haiderabbasi5233
    @haiderabbasi5233 Před 5 lety

    If we take the corner circle of radius 3 then is diameter will be 6 so as the height is 4 it will exceed the figure, which is not possible. If I’m wrong reply me ASAP.

    • @CornelisKok
      @CornelisKok Před 5 lety

      Just confirming that you are incorrect in the case of this video. The video shows a circle with diameter of 3, so it would fit in the space shown above.

  • @3k__kk
    @3k__kk Před 4 lety

    What Sources centroid of composite shapes???

  • @exral8797
    @exral8797 Před 2 lety

    thanks mate

  • @jayasreekandukuri2000
    @jayasreekandukuri2000 Před 2 lety

    How will find the Circle diameter is 3

  • @tinashe3082
    @tinashe3082 Před 4 lety +2

    how do you determine the centroid graphically?

    • @corneliskok7794
      @corneliskok7794  Před měsícem

      This is something that I don't know how to do yet. If you have found out, I would love to know.
      For a simple rectangle, you would draw lines from both of the opposite corners and the centroid would be at the intersection point. www.quora.com/How-do-you-find-the-centroid-for-a-rectangle-How-do-you-find-the-centroid-for-a-parallelogram
      For a triangle, you would draw three lines. From the middle of the each edge, to the opposite vertex. czcams.com/video/HoXV2mvCD28/video.html
      For a circle, the answer doesn't come to mind at the moment.
      The graphical method for a composite shape would have to take into account the size of area for each section, then would the centroid would be closer to the section with more area... but yeah, I haven't seen a graphical method for this.

  • @andrewrae9964
    @andrewrae9964 Před 3 lety +1

    nice kok

  • @MomenMusameh
    @MomenMusameh Před 4 lety +2

    why we use negative sign for removed parts in composite area to determine the centroid????
    which is better to use vertical strip or horizontal strip in integration method to find the centroid ?
    ??
    which is easier to use integration method or composite area method to solve for centroid of composite area ?
    ??
    Please I want an answer to these three questions ♥ thank you

    • @corneliskok7794
      @corneliskok7794  Před 3 lety +2

      *Why we use negative sign for removed parts in composite area to determine the centroid????
      When area is removed from a section, the center of the shape will move more towards the side that has more area.
      Which is better to use vertical strip or horizontal strip in integration method to find the centroid ?
      ??
      This depends on the function and which axis the section is bound by. If it is bound by the x-axis, I would use a vertical strip. If it is bound by the y-axis, I would use a horizontal strip. If it is bound between two functions, I would use whatever makes the intergration easier, or what ever allows you to minimise the number of equations you need to solve. This is easier to explain with an example.
      Which is easier to use integration method or composite area method to solve for centroid of composite area ?
      ??
      In this case it was the composite area method. If you know the function, the integration is useful as long as the integral can be solved (though you can solve for the area using numerical methods).

  • @jessealmontetanjusay8886

    Why'd you multiply 1/3 to find y of triangle instead of 2/3?

    • @corneliskok7794
      @corneliskok7794  Před 5 lety +1

      Sorry if this doesn't make sense or does not answer your question. I'm finding it quite hard to find out what may be your current concept, but I'll do what I can.
      There is a list of useful formulae for finding centroids available at the following link: en.wikipedia.org/wiki/List_of_centroids
      The formula shown in this link shows where the centroid is located in relation to the bottom right corner. In this case, our measurement is from the bottom left corner of the triangle.
      From that formulae we see that the centroid is located closer to the right angle corner '1/3 of the height' as measured from the bottom right, and '2/3' of the height as measured from the top right.
      One possible thing you may need to consider: the y co-ordinate is measured from the reference point on the bottom left corner of the triangle, and in the vertical direction
      the x co-ordinate is measured from the reference point on the bottom left corner of the triangle and in the horizontal direction.

  • @user-xz1uo2ow3h
    @user-xz1uo2ow3h Před 4 lety +1

    Please tell me from any source this question? Where can I find help?

    • @corneliskok7794
      @corneliskok7794  Před 4 lety

      This question was made up on the spot.
      A reference that I have used is Engineering Statics by Meriam and Kraige

    • @user-xz1uo2ow3h
      @user-xz1uo2ow3h Před 4 lety

      @@corneliskok7794
      I did not find him in Miriam?
      In which edition of Myriam can be obtained and what is chapter ?

  • @JoeHernandez-lp2tw
    @JoeHernandez-lp2tw Před rokem +1

    I would like to mention to take into account of where is your origin when using this method. My teacher for example gave me an exam where to shapes were on the left on the negative x while the other was on the right. I didn't see right and assumed everything was on the left and on the positive x range. Anyways with that mistake I made sure not to repeat that same mistake on the final :)

    • @corneliskok7794
      @corneliskok7794  Před rokem

      I definitely agree with this comment. In the example above I assumed that the origin is on the bottom left corner.

  • @jabezmoodley4559
    @jabezmoodley4559 Před 4 lety +1

    My calculator doesn't give me the correct decimals it's like .5 it doesn't like give .67 if my decimals are of a little does it mean my answers tally will be incorrect making everything wrong ?

    • @corneliskok7794
      @corneliskok7794  Před 4 lety

      It depends on the percentage error that would be created by the incorrect rounding (which in this case is caused by your calculator).
      for example if the number was 100.5 instead of 100.67... this situation would have less error created by your calculation than a situation where.... the number was 0.5 instead of 0.67
      If you are sure that the error is because of your calculator, I would look into getting a new calculator. An alternative could be to use wolframalpha.com or you could use calculator apps (I can't recommend one in particular though). Some of these options would not be appropriate in a controlled assessment. Maybe someone who is watching the page could suggest other alternatives.

  • @samkelobuthelezi1165
    @samkelobuthelezi1165 Před 3 lety

    Can you please do more videos

  • @travoltavatileni7494
    @travoltavatileni7494 Před měsícem

    Sir for the Area of the circle, the radius in 1.5 not 3. And why did Sir divide the area of the circle by 4?

    • @corneliskok7794
      @corneliskok7794  Před měsícem

      There is an equation for area of a circle using radius: pi * radius * radius
      And an equation for area of a circle using diameter: pi * diameter * diameter / 4
      It is more common that the diameter of objects are given rather than the radius so the second formula is more useful. A google search will also provide you with the same formula as I have used. "Area of a circle using diameter"

  • @mohammadzaher2737
    @mohammadzaher2737 Před 5 lety

    شكرا

  • @gajulavenkateswarlu3717

    Good sir place make more videos

  • @full-metal_jacob5858
    @full-metal_jacob5858 Před 6 lety +5

    why divide by 4?
    3:00

    • @corneliskok7794
      @corneliskok7794  Před 6 lety +9

      There is an equation for area of a circle using radius: pi * radius * radius
      And an equation for area of a circle using diameter: pi * diameter * diameter / 4
      It is more common that the diameter of objects are given rather than the radius so the second formula is more useful. A google search will also provide you with the same formula as I have used.
      bfy.tw/FPDf

    • @full-metal_jacob5858
      @full-metal_jacob5858 Před 6 lety +1

      superb explanation! thanks for going the extra mile!!!

  • @cameronarnold7279
    @cameronarnold7279 Před 5 lety +2

    why did he divide area of circle by 4?

    • @corneliskok7794
      @corneliskok7794  Před 5 lety +2

      Hi Cameron, thanks for your question. There was a previous comment that asked me the same question so I can answer this quickly.
      There is an equation for area of a circle using radius: pi * radius * radius
      And an equation for area of a circle using diameter: pi * diameter * diameter / 4
      It is more common that the diameter of objects are given rather than the radius so the second formula is more useful. A google search will also provide you with the same formula as I have used.
      bfy.tw/FPDf

  • @anujnair3379
    @anujnair3379 Před 6 lety

    When to use formula 2h/ 3 to solve

    • @corneliskok7794
      @corneliskok7794  Před 6 lety +1

      Hi Anuj, there is a list of centroids for common shapes available from wikipedia: en.wikipedia.org/wiki/List_of_centroids
      The equation h/3 is used for finding the distance from the right angle side to the center in the vertical direction. 2h/3 is usually used for finding the distance from the other side. I'm finding this quite hard to explain in text so the first image in the following link may help you: www.engineeringintro.com/mechanics-of-structures/centre-of-gravity/centroid-of-triangle/

  • @malikatalwrood510
    @malikatalwrood510 Před 5 lety

    I have a near example you can help me find a solution? Belize😫

  • @LuckyStrange
    @LuckyStrange Před 3 lety

    Why did you multiplied 2/3×8

    • @CornelisKok
      @CornelisKok Před 3 lety

      Sorry for the delay.
      That was because the centroid is 1/3 away from the right angle side and 2/3 of the length from the acute angle side. What is important is the location of the centroid of the triangle in relation to the co-ordinate system; the formula isn't the most important thing to focus on in this problem.

  • @princehenry1382
    @princehenry1382 Před 5 lety

    Why is the area of the circle negative ??

    • @corneliskok7794
      @corneliskok7794  Před 5 lety +1

      In this question, area is negative because it represents a section of the shape that is being taken away.

  • @shaunakkhair5097
    @shaunakkhair5097 Před 6 lety

    Why the circle's area is taken as negative?

    • @corneliskok7794
      @corneliskok7794  Před 6 lety +2

      Hi Shaunak, the question is made up of a triangle and rectangle with a circle hole removed. The circles area is taken as negative because it is removed from the triangle and rectangle section.

    • @bryanandujar3683
      @bryanandujar3683 Před 6 lety +1

      thank you for this answer

  • @tebogomokoena4371
    @tebogomokoena4371 Před 3 lety

    Why divide by 4 on the area of a circle hole?

    • @corneliskok7794
      @corneliskok7794  Před 3 lety +1

      There is an equation for area of a circle using radius: pi * radius * radius
      And an equation for area of a circle using diameter: pi * diameter * diameter / 4
      It is more common that the diameter of objects are given rather than the radius so the second formula is more useful. A google search will also provide you with the same formula as I have used.
      bfy.tw/FPDf

    • @den-kun1482
      @den-kun1482 Před 8 měsíci

      ​@@corneliskok7794Hello sir! I'm not sure but I think you put the radius (3) instead of the diameter which was supposed to be 6 in the formula pi(d/2)²

  • @ashnilabhatt6242
    @ashnilabhatt6242 Před 4 lety

    How to know wether area is negative or positive

    • @corneliskok7794
      @corneliskok7794  Před 4 lety

      If material is taken away from the section, then the area is negative.
      If material is added to the section, then the area is positive.
      (I'd like to use a different word to "material", but it is the most understandable word in this context)

  • @zetsu9823
    @zetsu9823 Před 5 lety

    Why circle area is negative?

    • @corneliskok7794
      @corneliskok7794  Před 5 lety

      Hi Skoosh brr, the question is made up of a triangle and rectangle with a circle hole removed. The circles area is taken as negative because it is removed from the triangle and rectangle section.

    • @zetsu9823
      @zetsu9823 Před 5 lety

      @@corneliskok7794 thanks sir

  • @shifazahera7099
    @shifazahera7099 Před 6 lety

    But for area of circle is pi.r^2

    • @CornelisKok
      @CornelisKok Před 6 lety

      Hi Shifa, you are correct. It is also (pi.d^2)/4
      czcams.com/video/koxdduRGOLk/video.html

    • @shifazahera7099
      @shifazahera7099 Před 6 lety

      Cornelis Kok ...ok actually i didn't observe that u have take diameter ok .. thank you

  • @harishjaiswal2832
    @harishjaiswal2832 Před 6 lety

    Triangle formula is 1/3 *B*H

    • @corneliskok7794
      @corneliskok7794  Před 6 lety +1

      Hi Harish, are you referring to the area of a triangle, the centroid of a triangle, or some other concept?

  • @rubeushagridplayslol
    @rubeushagridplayslol Před rokem

    isn't it supposed to be cm not mm

  • @hasnainali-fg2wq
    @hasnainali-fg2wq Před 4 lety

    Why negative atea

    • @corneliskok7794
      @corneliskok7794  Před 4 lety

      Hi Hasnian Ali,
      In this question, area is negative because it represents a section of the shape that is being taken away.

    • @travoltavatileni7494
      @travoltavatileni7494 Před měsícem

      @@corneliskok7794 Why did sir divide the area of the circle by 4?

  • @sabeloshikwambana6472
    @sabeloshikwambana6472 Před 4 lety

    Tf going on

    • @corneliskok7794
      @corneliskok7794  Před 3 lety

      If we cut this shape from a piece of cardboard, I'm trying to find the place where we could balance that shape on the tip of a pin

  • @mdlsaabfashion3812
    @mdlsaabfashion3812 Před 5 lety +1

    its not a good explanation sir g for civil

    • @CornelisKok
      @CornelisKok Před 5 lety

      Thanks for your comment! What is missing?

    • @waleedjaved9905
      @waleedjaved9905 Před 5 lety

      What are u smoking mate ? This guy explained everything really good.

    • @TheHonchoofAllSpearheads
      @TheHonchoofAllSpearheads Před 5 lety

      atif wafa bcoz ü will nvr understand even the simplest thing?