Centroid Question: Understanding & Measuring Distance

  • Thread starter Thread starter Ry122
  • Start date Start date
  • Tags Tags
    Centroid
Ry122
Messages
563
Reaction score
2
I'm having trouble understanding what this question is actually asking for. Is it assuming the centroid to be the origin and asking how far the bottom of the shape extends downwards for the origin to be the centroid?
z84dCnC.jpg
 
Physics news on Phys.org
Ry122 said:
I'm having trouble understanding what this question is actually asking for. Is it assuming the centroid to be the origin and asking how far the bottom of the shape extends downwards for the origin to be the centroid?
No, I don't think so. To the best of my interpretation of the question, it contains two parts:
(1) Given this shape, find out the position of the centre of mass (in terms of L).
(2) From that answer, determine the range of values of L such that the centre of mass lies in the shape itself (i.e. L \leq y_{c} \leq 0)
 
Ry122 said:
I'm having trouble understanding what this question is actually asking for. Is it assuming the centroid to be the origin and asking how far the bottom of the shape extends downwards for the origin to be the centroid?
Not exactly that, but if you were to answer that question it would be a short step to answering the last part of the given question. Wouldn't help so much with the first part though, so address that first.
 
The figure is described completely and you are asked to find the centroid. So, no, the problem does not assume the centroid is at the origin! The centroid of a region always lies within it convex hull but for some values of L, the centroid might lie just above the origin, outside the figure itself.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top