GCSE Physics: Energy and Energy Resources

Vocabulary flashcards covering energy stores, energy equations, conservation of energy, power, efficiency, and energy resources.

System

An object or a group of objects.

Kinetic Energy

The energy stored in an object due to its motion, calculated using the equation $E_k = \frac{1}{2} m v^2$.

Elastic Potential Energy

The energy stored in an elastic object (such as a spring) when it is stretched, calculated using $E_e = \frac{1}{2} k e^2$.

Gravitational Potential Energy

The energy stored in an object due to its position in a gravitational field, calculated using $E_p = m g h$.

Specific Heat Capacity

The amount of energy required to raise the temperature of $1\,\text{kg}$ of a substance by $1\,^\circ\text{C}$ (or $1\,\text{K}$), given by $E = m c \Delta T$.

Power

The rate at which energy is transferred or the rate at which work is done, calculated as $P = \frac{E}{t} = \frac{W}{t}$.

Watt

The unit of power, where an energy transfer of $1\,\text{joule}$ per second is equal to a power of $1\,\text{watt}$.

Conservation of Energy

The principle stating that energy cannot be created or destroyed, only transferred usefully, stored, or dissipated.

Wasted Energy

Energy that is transferred into a form that is not the desired outcome and is dissipated into less useful stores.

Efficiency

The ratio of useful energy (or power) output to total energy (or power) input, often expressed as a percentage.

Lubrication

A method to reduce unwanted energy transfers by reducing friction (such as using oil in a motor) so less energy is dissipated as heat.

Thermal Insulation

Techniques or materials (such as double glazing) that decrease the rate of cooling and reduce the loss of useful thermal energy.

Thermal Conductivity

A measure of how easily heat travels through a material; higher thermal conductivity leads to a higher rate of energy transfer by conduction.

Non-renewable Energy Resource

An energy resource that cannot be replenished as it is used and will eventually run out, such as fossil fuels and nuclear fuel.

Fossil Fuels

Non-renewable fuels consisting of coal, oil, and gas, the combustion of which produces greenhouse gases that contribute to global warming.

Nuclear Power

A non-renewable energy source that does not release $\text{CO}_2$ but generates radioactive waste that must be contained.

Renewable Energy Resource

An energy resource that is replenished as it is used and never runs out (such as wind, solar, and hydroelectricity), typically causing less environmental damage.