Energy

Energy is a fundamental concept in physics describing the capacity of a system to do work.

Energy is a fundamental concept in physics, describing the capacity of a system to do work. It is a scalar quantity measured in joules (J) in the International System of Units, and it can appear in forms such as kinetic, potential, thermal, chemical, electrical, and nuclear energy. In physics, energy is conserved: it can be transformed from one form to another, but not created or destroyed.

Definition

In physics, energy is commonly defined as the capacity for doing work or producing change in a system. It is a physical quantity that allows a system to exert forces and cause displacement. Energy is a scalar quantity, meaning it has magnitude but no direction.

Forms of energy

Energy exists in multiple forms. Kinetic energy is the energy of motion, while potential energy is stored energy based on position or configuration. Other common forms include thermal, electrical, chemical, and nuclear energy. These forms can be converted from one to another.

Measurement and units

The SI unit of energy is the joule (J). As a scalar quantity, energy is described solely by its magnitude and does not have a direction. Energy measurements are fundamental in physics and engineering.

Conservation of energy

The law of conservation of energy is a core principle in physics. It states that energy cannot be created or destroyed; it can only be transformed from one form to another or transferred between systems. In an isolated system, the total energy remains constant.

Energy in Canada

In Canada, energy is a central topic in science education, engineering, and energy policy. Discussions often involve electricity generation, fossil fuels, hydroelectricity, nuclear power, and renewable energy systems. The principles of energy conservation and transformation are applied across these sectors.