A body of mass m is acted upon by a central force \(\vec{f}(\vec{r})=-k \vec{r}\), where k is a positive constant. If the magnitude of the angular momentum is l, then the total energy for a circular orbit is
1
\(2 \sqrt{\frac{k l^2}{m}}\)
2
\(\frac{1}{2} \sqrt{\frac{k l^2}{m}}\)
3
\(\frac{3}{2} \sqrt{\frac{k l^2}{m}}\)
4
\(\sqrt{\frac{k l^2}{m}}\)