Equations

**matt_crouch** · Nov20-09, 05:26 AM

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

F_x=e²/ 4 $LaTeX Code: \\pi$ $LaTeX Code: \\epsilon$ ₀x²

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

?

btw the pi and E are not raised to the power its just my inability to use latex =]

**Doc Al** · Nov20-09, 05:38 AM

Originally Posted by matt_crouch

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

F_x=e²/ 4 $LaTeX Code: \\pi$ $LaTeX Code: \\epsilon$ ₀x²

This looks like the force between two point charges.

is similar to F_x= -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.

**matt_crouch** · Nov20-09, 05:51 AM

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

**Doc Al** · Nov20-09, 06:46 AM

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

**matt_crouch** · Nov20-09, 08:08 AM

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