Calculating Change in Free Energy from Rod Displacement

[Gavroy]

hi

i have a question concerning free energy

in the attached file you can see 3 rods.

think of them as 3 parallel forces, that attract each other by a force F.

the force is some arbitrary force of the form: F=a/r^6 where a is a real parameter

now imagine that caused by fluctuations(e.g. thermal fluctuations etc.) the rod is bent, which results in a change of the force fields, as one part of the rod approaches the right rod, while it leaves the potential of the force field of the left rod. ( this is exactly what you see in the image)

now the question is: what is the change in free energy caused by this displacement.

i actually calculated the change in free energy caused by the elasticity of the rod and now i want to include this force field.

my guess is, that it is just the work done by the rod, when it moves out of one potential and approaches the other one, but i am not sure at all.

what do you think about this?

(sorry about my english, but i do not linve in an english speaking country)

 

[Valerie Park]

I think that it is possible to calculate the change in free energy caused by the displacement of the rod. To do this, you need to calculate the change in potential energy due to the change in force field. This can be done by calculating the difference in force between the left and right rods at different positions of the rod. Once you have calculated this, you can then use the Work-Energy Theorem to determine the work done on the rod, which can be related to the change in free energy.