# Fx= -du/dx does the e2=-du

1. Nov 20, 2009

### matt_crouch

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

Fx=e2/ 4$$\pi$$$$\epsilon$$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 =]

2. Nov 20, 2009

### Staff: Mentor

Re: Equations

This looks like the force between two point charges.

No. Why do you think these equations are mathematically similar?

That's because you're mixing latex and non-latex within an equation. Write the equation using only latex.

3. Nov 20, 2009

### matt_crouch

Re: Equations

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 im getting confused

4. Nov 20, 2009

### Staff: Mentor

Re: Equations

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

5. Nov 20, 2009

### matt_crouch

Re: Equations

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