Question

If the potential energy of two molecules is given by \(\sf U=\frac{A}{r^{12}} - \frac{B}{r^6}\)then at equilibrium position, its potential energy is equal to

Answer 1

Answer given is \(\sf \frac{-B^2}{4A}\)

Answer 2

try this

\[ \frac{dU}{dr}=\frac{-12A}{r^{13}}+\frac{6B}{r^7} = 0\]
\[r_e^6 = \frac{2A}{B}\]
\[ U_e=\frac{A}{(\frac{2A}{B})^2}−\frac{B}{\frac{2A}{B}}\] etc

Answer 3

Thanks c: