Key Concepts in Work, Energy and Power Energy Energy is the capacity to do work. This topic covers several forms of energy: Kinetic Energy - The energy of motio...
Energy is the capacity to do work. This topic covers several forms of energy:
Energy cannot be created or destroyed, but can be transformed from one form to another. The total energy of an isolated system remains constant.
A roller coaster cart has maximum kinetic energy at the bottom of a drop and maximum gravitational potential energy at the top. Energy is transformed between these forms, but the total energy is conserved (neglecting friction).
Work is done when a force displaces an object. The work-energy theorem states that the net work done on an object equals its change in kinetic energy.
Work = Force × Displacement × Cosine(angle)
Power is the rate of energy transfer or work done. It is calculated as work done per unit time.
Power = Work done / Time
Efficiency measures the ratio of useful energy output to total energy input for a process. Inefficiencies lead to energy dissipation as heat.