Conservation of Energy

Law of Conservation of Energy

Energy can neither be created nor destroyed, only transformed into different forms. The total energy of an isolated system remains constant.

Energy Stores

Various forms of energy storage include Kinetic, Potential, Chemical, Thermal, Nuclear, Electrostatic, and Magnetic energy.

Energy Transfer Pathways

Energy is transferred between stores through pathways like mechanical working, electrical working, heating by particles, and heating by radiation.

Energy Flow Diagram

A tool representing energy stores and transfers within a system.

Gravitational Potential Energy

Energy stored in an object's gravitational field due to its height, calculated as ΔGPE = m × g × Δh.

Kinetic Energy

Energy associated with the motion of an object, calculated as KE = ½ x m x v².

Closed Systems

A system where the total energy remains constant, with no net change in energy within the system.

Law of Conservation of Energy

States the idea that energy can neither be created nor be destroyed. Although, it can change into a different forms.

Émilie du Châtelet

Who was the French mathematician and philosopher who first postulated and tested the concept of the law of conservation of energy in the 18th century?

Kinetic Energy

the energy associated with the motion of an object. The faster an object moves, the more kinetic energy it possesses.

Potential Energy

the energy stored in an object based on its position or state. Energy depends on an object's height, and elastic potential energy is stored in objects that can be stretched or compressed.

Chemical Energy

energy stored in the bonds between atoms and molecules. This energy is released during chemical reactions.

Thermal Energy

the internal energy of a system due to the random motion of its particles. It is associated with the temperature of an object.

Nuclear Energy

energy stored in the nucleus of an atom. It can be released through nuclear reactions, such as fission or fusion.

Electrostatic Energy

energy stored in charged particles due to their positions relative to each other.

Magnetic Energy

energy stored in a magnetic field. It is associated with the alignment and motion of magnetic materials.

Mechanical working

when a force acts on an object e.g. pulling, pushing, stretching, squashing.

Electrical working

a charge (current) moving through a potential difference e.g. charge flowing around a circuit.

Heating by particles

energy is transferred from a hotter object to a colder one

Heating by radiation

energy transferred by electromagnetic waves, e.g. Light.

Sankey Diagrams

One way to depict energy transfers is with

System

is defined in physics as an item or collection of items.

Joules (J)

Energy is measured in units of

10 N/kg

On Earth, the gravitational field strength (g) is about

ΔGPE = m × g × Δh

Where:

ΔGPE is the gravitational potential energy change, expressed in joules (J).

m = mass (kg) in kilogrammes

Gravitational field strength, or g = measured in newtons per kilogramme (N/kg).

Change in vertical height in metres (m) equals Δh.

The Greek letter "delta" (Δ) in physics stands for "change in.”

KE = ½ x m x v²

Where:

J (Joules) is the unit of kinetic energy (KE).

m = the object's mass in kilogrammes (kg)

v is the object's speed in metres per second (m/s).