- #1
DrummingAtom
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Homework Statement
The potential energy of a pair of atoms separated by a large distance x is given by U(x) = -C6/x6, where C6 is a positive constant. What is the force that one atom exerts on the other? Is this force attractive or repulsive?
Homework Equations
F(x) = -dU/dx
The Attempt at a Solution
The force I got is:
F = -6C6/x7
I'm confused by the second question of is the force attractive or repulsive. Seeing that there's a negative sign, one must be moving toward the other. Although, the potential energy graph says it's going to be a large negative U at a small distance. Which shouldn't it be a small positive U at a small distance? Thanks for any help.