Educator

Conservation of Energy, Part 1

• A system is isolated if it does not exchange energy with its surroundings.
• The total energy of an isolated system is constant in time.
• Energy may be transformed from one form to another. For example, potential energy may be transformed to kinetic energy.
• When a block is attached to one end of a spring and set oscillating, then at any one instant in time the system will have a kinetic energy K given by (1/2)(mass)(velocity squared) and an elastic potential energy U given by (1/2)(force constant k)(displacement from equilibrium, squared). But the sum K+U remains constant; it does not change as time goes by.