Centroid of a Composite Shape - Tabular Method - Part 1
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- Опубліковано 23 сер 2024
- 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...
just gets straight to the fking point, excellent video has helped me greatly! keep up the good work
Thank you so much finally after trolling through UA-cam I have found somebody able to explain this to me
sir, this is very helpful and plz make more videos on this topic
Very nice explaination . Loved it
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
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)
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
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.
nice explanation indeed
sir this is really helpful for me thanks
Glad this helped. No worries.
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 :)
I definitely agree with this comment. In the example above I assumed that the origin is on the bottom left corner.
nice MR HELPED ME A LOT GOOD EXPLANATIONS THUMBS UPPPP
nice kok
isnt the centroid of a triangle the 1/3rd and not the 2/3rds as you put?
thank youuuuuuu
Great explanation
Please do more videos of this topic 🙏
Very useful
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
*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).
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?
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"
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 ?
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.
Great stuff thanks...
You're welcome
thanks mate
why did he divide area of circle by 4?
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
good explanation
why divide by 4?
3:00
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
superb explanation! thanks for going the extra mile!!!
How will find the Circle diameter is 3
how do you determine the centroid graphically?
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. ua-cam.com/video/HoXV2mvCD28/v-deo.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.
Please tell me from any source this question? Where can I find help?
This question was made up on the spot.
A reference that I have used is Engineering Statics by Meriam and Kraige
@@corneliskok7794
I did not find him in Miriam?
In which edition of Myriam can be obtained and what is chapter ?
Why'd you multiply 1/3 to find y of triangle instead of 2/3?
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.
What Sources centroid of composite shapes???
شكرا
you're welcome. Thanks for watching
Good sir place make more videos
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.
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.
Why did you multiplied 2/3×8
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.
Can you please do more videos
How to know wether area is negative or positive
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)
Triangle formula is 1/3 *B*H
Hi Harish, are you referring to the area of a triangle, the centroid of a triangle, or some other concept?
Why is the area of the circle negative ??
In this question, area is negative because it represents a section of the shape that is being taken away.
Why divide by 4 on the area of a circle hole?
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
@@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
I have a near example you can help me find a solution? Belize😫
Hi Malikat, please post it here.
When to use formula 2h/ 3 to solve
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/
Why the circle's area is taken as negative?
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.
thank you for this answer
But for area of circle is pi.r^2
Hi Shifa, you are correct. It is also (pi.d^2)/4
ua-cam.com/video/koxdduRGOLk/v-deo.html
Cornelis Kok ...ok actually i didn't observe that u have take diameter ok .. thank you
Why circle area is negative?
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.
@@corneliskok7794 thanks sir
isn't it supposed to be cm not mm
You can always convert
Why negative atea
Hi Hasnian Ali,
In this question, area is negative because it represents a section of the shape that is being taken away.
@@corneliskok7794 Why did sir divide the area of the circle by 4?
Tf going on
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
its not a good explanation sir g for civil
Thanks for your comment! What is missing?
What are u smoking mate ? This guy explained everything really good.
atif wafa bcoz ü will nvr understand even the simplest thing?