Centroid Position of a Lamina Bounded by a Curve

In summary, we are given a lamina bounded by the x-axis, y-axis, and the curve ##y = 4-x^2## and we need to determine the centroid position ##(\bar{x},\bar{y})## of the lamina. Using the equations for finding the centroid position, we first determine the limits for the integration to be a=0 and b=2. Then, substituting these values into the equations, we get ##A=16/3## for the area, ##\bar{x} = \frac{3}{4}## for the x-coordinate of the centroid, and ##\bar{y} = \frac{8}{5}## for the y-coordinate. Therefore,
  • #1
Alex_Neof
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Homework Statement



A lamina is bounded by the x-axis, the y-axis, and the curve ##y = 4 -x^2.## Determine the centroid position ##(\bar{x},\bar{y})## of the lamina.

Homework Equations



## A = \int_a^b (f(x) - g(x)) dx ## (Area)

##\bar{x} = \frac{1}{A}\int_a^b x(f(x) - g(x)) dx ##

##\bar{y} = \frac{1}{A}\int_a^b \frac{1}{2}(f(x)^2 - g(x)^2) dx ##

The Attempt at a Solution



I made a sketch and determined ## a = 0## and ##b = 2 ## for the limits.

Then just plugged into the above equations.

With this I determined the area to be ##A=16/3##

##\bar{x} = \frac{3}{4} ##

##\bar{y} = \frac{8}{5}##

Therefore centroid position is ##(\frac{3}{4},\frac{8}{5})##

Could someone kindly verify this?
 
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  • #2
Everything looks good at a glance.
 
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Likes Alex_Neof
  • #3
It is correct, thank you :smile:. I used an online calculator to verify it. I'll write out a solution for any future viewers.
 

FAQ: Centroid Position of a Lamina Bounded by a Curve

What is the centroid position of a lamina?

The centroid position of a lamina is the point at which the lamina's weight is evenly distributed in all directions. It is the balance point of the lamina.

How is the centroid position of a lamina calculated?

The centroid position of a lamina can be calculated by finding the average of the x and y coordinates of all the points on the lamina. This can be done using the formula: x̄ = (∑(xi * Ai)) / (∑Ai) and ȳ = (∑(yi * Ai)) / (∑Ai), where x and y are the coordinates, A is the area, and i is the number of points.

Why is the centroid position important?

The centroid position is important because it helps determine the stability and balance of a lamina. It is also used in engineering and design to find the center of mass and to calculate moments of inertia.

How does the shape of a lamina affect its centroid position?

The shape of a lamina can greatly affect its centroid position. For symmetrical shapes, the centroid will be at the geometric center. However, for irregular shapes, the centroid may not be at the center and may need to be calculated using the formula mentioned above.

What are some applications of the centroid position of a lamina?

The centroid position of a lamina has many practical applications. It is used in structural engineering to determine the center of mass and stability of buildings and bridges. It is also used in physics and mechanics to calculate moments of inertia and rotational dynamics. Additionally, it is used in architecture and design to create balanced and aesthetically pleasing structures.

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