Need help with graphs of potential energy and force

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Homework Help Overview

The problem involves analyzing the potential energy function U(x) of a point mass and deriving the corresponding force function F(x) from it. The potential energy is defined as U(x) = Uo * xo * x / (x² + xo²), where Uo and xo are positive constants. Participants are tasked with graphing both U(x) and F(x).

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the derivation of the force function F(x) from the potential energy U(x) and share their attempts at graphing these functions. Questions arise regarding the graphical representation of F(x) and the characteristics of U(x), including its asymptotic behavior.

Discussion Status

Some participants have provided their findings for F(x) and U(x), while others are seeking clarification and further exploration of the graphs. There is an ongoing dialogue about the methods used for graphing and the interpretation of the functions' behaviors.

Contextual Notes

Participants are encouraged to describe their graphical attempts and the tools used, as well as to consider the asymptotic behavior of U(x) in relation to F(x). There is an emphasis on understanding the relationships between the two functions without relying solely on plotting tools.

Spyridoula
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Hi everyone!

Homework Statement



The potential energy U of a point mass is U(x)= Uoxo x/(x2 + xo2) where Uo and xo are positive contants, Uo in joule and x,xo in meters. Draw the graphs of U(x) and F(x).

Homework Equations



F(x) = -dU/dx

The Attempt at a Solution



I found the F(x) function and made the U(x) graph but I'm stuck with the F(x) graph and I'm not totally sure for anything that I found so far.

Thank you!
 
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Please post what you got for the F(x) function. For the graphs, either post your attempts or at least a verbal description.
 
For the F(x) I found that it is V0x0 (x+x0)(x-x0) / (x2 + x02)2

I can't make a graph out of it. As for the U(x) the graph is in the attachment below.
U(x)=0 when x=0 and Vmax=V0/2 when x=x0
 

Attachments

  • MSP341911a40ca99741cac38000060i1bef752e64i66.gif
    MSP341911a40ca99741cac38000060i1bef752e64i66.gif
    2 KB · Views: 493
When sketching a graph, you should take it far enough to illustrate asymptotic behaviour. What is that for U(x)?
I don't understand why cannot get a graph for F. What tool did you use to get the graph for U? You ought to be able to sketch graphs from the formula without using a plotting tool. That's how you know which sections are interesting to plot.
Can you at least describe in words what F(x) would look like by inspection of the U(x) graph? Say what the asymptotic values are, over what ranges it would be positive, where the zeroes are, and all extrema.
 

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