* Equilibrium: The meter rod is in equilibrium because the net force and net torque acting on it are zero. It's not moving.
* Unstable: If you were to slightly displace the rod from its balanced position, it would immediately fall to one side. This is because the center of gravity of the rod is above the point of support (the wedge), making the system inherently unstable. Any slight disturbance will lead to a restoring force that pushes the rod further away from its equilibrium position.
Think of it like this: Imagine balancing a pencil on its tip. It's possible to get it perfectly balanced for a moment, but the slightest breeze will send it tumbling over.
Contrast with Stable and Neutral Equilibrium:
* Stable: If you displace the rod, it would return to its original position. A ball in a bowl is an example of stable equilibrium.
* Neutral: If you displace the rod, it would remain in its new position. A ball on a flat surface is an example of neutral equilibrium.
