Potential-Energy Criterion for Equilibrium

Potential energy or potential function plays an essential role in determining the stability of a mechanical system. If a system is subjected to both gravitational and elastic forces, the potential function of the system can be expressed as the algebraic sum of gravitational and elastic potential energy. If the system is in equilibrium and is dis...

Consider a frictionless spring-mass system whose position is defined by one independent variable. Here, the potential energy is the sum of the gravitational and elastic potential energies, and the negative of its change equals the work done on the system.

If the system is in equilibrium and undergoes a virtual displacement, the work done ...