Question

an elastic spring of spring constant K is compressed by an amount X obtain an expression for its potential energy.

Answer 1

Potential energy is energy that is stored in a system. There is the possibility, or potential, for it to be converted to kinetic energy. Elastic potential energy is stored in a spring that has been stretched or compressed by a distance x away from its equilibrium position. Position x = 0 must always be the position where the spring is most relaxed. Springs have their own natural "spring constants" that define how stiff they are. The letter k is used for the spring constant, and it has the units N/m. Like all work and energy, the unit of potential energy is the Joule (J), where 1 J = 1 N∙m = 1 kg m2/s2 .