Are Fx= -du/dx and Fx=e2/ 4\pi\epsilon0x2 Mathematically Similar?

  • Context: Undergrad 
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Discussion Overview

The discussion revolves around the mathematical similarity of two equations related to force: Fx = e² / (4πε₀x²) and Fx = -du/dx. Participants explore whether these equations can be considered equivalent or similar in their mathematical form and implications, particularly in the context of forces between point charges and potential energy calculations.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Mathematical reasoning

Main Points Raised

  • Some participants question the mathematical similarity of the equations, specifically whether e² can be equated to -du.
  • One participant notes that Fx = e² / (4πε₀x²) represents the force between two point charges.
  • Another participant explains that to find potential energy from force, one can use the relationship F = -dU/dx, leading to U = -∫F(x) dx.
  • A participant expresses confusion stemming from a lecture on calculating potential energy and the forces acting between atoms, specifically in the context of sodium chloride.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether the two equations are mathematically similar. There is a mix of agreement on the use of the equations in calculating potential energy, but disagreement on their equivalence.

Contextual Notes

Participants mention the importance of using consistent notation (latex vs. non-latex) in equations, which may affect clarity in understanding the mathematical relationships.

matt_crouch
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im unsure about if two equations are mathematically similar whether they equal the same. ill give an example

Fx=e2/ 4[tex]\pi[/tex][tex]\epsilon[/tex]0x2

is similar to Fx= -du/dx does the e2=-du

?

btw the pi and E are not raised to the power its just my inability to use latex =]
 
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matt_crouch said:
im unsure about if two equations are mathematically similar whether they equal the same. ill give an example

Fx=e2/ 4[tex]\pi[/tex][tex]\epsilon[/tex]0x2
This looks like the force between two point charges.

is similar to Fx= -du/dx does the e2=-du
No. Why do you think these equations are mathematically similar?

btw the pi and E are not raised to the power its just my inability to use latex
That's because you're mixing latex and non-latex within an equation. Write the equation using only latex.
 


when calculating the distance between atoms in a structure. in the lecture we used sodium chloride an the force acting on the to calculate the potential energy and therefore the energy used to break the bonds. so we intergrated the force between two points equation and calculated the potential energy
this is why I am getting confused
 


Given the force, F(x), you can find the potential energy using F = -dU/dx. Thus:
U = - ∫F(x) dx
 


ok i see. makes sense
thanks for clearing that up
cheers
 

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