What does ##\bar{x}_{\textrm{el}}## represent?

In summary, ##\bar{x}_{\textrm{el}}## and ##\bar{y}_{\textrm{el}}## represent the location of the centroid of a small element used to calculate the first moments of length or area. This notation is commonly used in engineering textbooks, such as Vector Mechanics for Engineers by Ferdinand P. Beer and E. Russell Johnston Jr. An example problem using this notation can be found on page 1 of the resource provided.
  • #1
END
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In the context of centroids and moments, what do ##\bar{x}_{\textrm{el}}## and ##\bar{y}_{\textrm{el}}## represent?

For example:

$$\bar{x}L = \int \bar{x}_{\textrm{el}}dL$$
 
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  • #2
The integral itself looks like a first moment, where the integrand is a function of position. I have no idea where this came from, so I can't go into any more detail.
 
  • #3
mathman said:
I have no idea where this came from, so I can't go into any more detail.

Thanks for your response, mathman.

Here are some resources that utilize this notation:

  1. (page 1) http://www.sut.ac.th/engineering/Civil/CourseOnline/430201/pdf/05_review.pdf
  2. Vector Mechanics for Engineers:Statics and Dynamics by Ferdinand P. Beer & E. Russell Johnston J.
Below is an example problem Beer's

Qf4BF.png
 
  • #4
END said:
In the context of centroids and moments, what do ##\bar{x}_{\textrm{el}}## and ##\bar{y}_{\textrm{el}}## represent?

For example:

$$\bar{x}L = \int \bar{x}_{\textrm{el}}dL$$

xEL and yEL represent the location of the centroid of a tiny element of length dL or a tiny element of area dA used to calculate the first moments of length or area.

Study pp. 1 and 2 of the link carefully. :wink:
 

Related to What does ##\bar{x}_{\textrm{el}}## represent?

1. What is ##\bar{x}_{\textrm{el}}## in statistics?

##\bar{x}_{\textrm{el}}## is a symbol used in statistics to represent the sample mean of a set of data. It is calculated by finding the sum of all the data points and dividing by the total number of data points in the sample.

2. How is ##\bar{x}_{\textrm{el}}## different from ##\bar{x}##?

##\bar{x}_{\textrm{el}}## specifically represents the sample mean of a set of data, while ##\bar{x}## can represent both the sample mean and the population mean. The population mean takes into account all possible data points, while the sample mean only considers a subset of the data.

3. Can ##\bar{x}_{\textrm{el}}## be negative?

Yes, ##\bar{x}_{\textrm{el}}## can be negative if the data set includes negative values. It is important to note that the sign of ##\bar{x}_{\textrm{el}}## does not indicate the overall trend of the data, but rather the average value of the data points.

4. How is ##\bar{x}_{\textrm{el}}## used in hypothesis testing?

In hypothesis testing, ##\bar{x}_{\textrm{el}}## is used to calculate the test statistic, which is then compared to a critical value to determine the significance of the results. It is also used to calculate confidence intervals, which help to estimate the true population mean.

5. What are some common misconceptions about ##\bar{x}_{\textrm{el}}##?

One common misconception is that ##\bar{x}_{\textrm{el}}## represents the only possible value for the mean of a data set. In reality, there are infinite possible values for the mean, and ##\bar{x}_{\textrm{el}}## is just one estimation based on the sample. Another misconception is that ##\bar{x}_{\textrm{el}}## is always a whole number, when in fact it can be a decimal or fraction depending on the data set.

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