A wedge of mass M fitted with a spring of stiffness 'k' is kept on a smooth horizontal surface. A rod of mass m is kept on the wedge as shown in the figure. System is in equilibrium and at rest. Assuming that all surfaces are smooth, the potential energy stored in the spring is:
![1067559_98914c4ff64848aea3d6308a27d94408.png](https://search-static.byjusweb.com/question-images/toppr_invalid/questions/1067559_98914c4ff64848aea3d6308a27d94408.png)