Potential energy as a function of \( r \) is given by \( U=\frac{A}{r^{10}}-\frac{B}{r^{5}} \), where \( r \) is the interatomic distance, \( A \) and \( B \) are positive constants. The equilibrium distance between the two atoms will be:
\( \left(\frac{A}{B}\right)^{\frac{1}{5}} \)
\( \left(\frac{B}{A}\right)^{\frac{1}{5}} \)
\( \left(\frac{2A}{B}\right)^{\frac{1}{5}} \)
\( \left(\frac{B}{2A}\right)^{\frac{1}{5}} \)
