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The potential energy of a system of two particles is given by \mathrm{v=-\frac{m}{r^{2}}+\frac{n}{r^{8}}}, where \mathrm{r} between the particle and \mathrm{m} and \mathrm{n} are positive constant. If the system is in equilibrium at \mathrm{r=r_{0}} then \mathrm{r_{0}} in terms of \mathrm{m} and \mathrm{n}.

Option: 1

r_{0}^{3}=2 \sqrt{\frac{n}{m}}


Option: 2

r_{0}^{3}=2 \frac{n}{m}


Option: 3

r_{0}^{3}=\frac{4 n}{m}


Option: 4

r_{0}^{3}=8 \frac{n}{m}


Answers (1)

best_answer

For equilibrium -

\left.\frac{d V}{d r}\right|_{r=r_{0}}=0 \\

\mathrm{\frac{d}{d r}\left[-m r^{-2}+n r-8\right]_{r=r_{0}}=0}
\mathrm{{\left[2 m r^{-3}-8 n r^{-9}\right]_{\gamma=r_{0}}=0}}
\mathrm{{2 m r_{0}^{-3}=8 n r_{0}^{-9}}
\mathrm{\frac{r_{0}^{-3}}{r_{0}-9}=\frac{8 n}{2 m}}
\mathrm{r_{0}^{-3+9}=\frac{4 n}{m} }
\mathrm{r_{0}^{6}=\frac{4 n}{m} \Rightarrow r_{0}^{3}=\sqrt[2]{\frac{n}{m}} }  Ans.

Posted by

SANGALDEEP SINGH

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