1. GCSE Physics - Energy

Energy transfer

The movement of energy from one store/object to another.

Kinetic energy

Energy stored by an object's motion

The equation for kinetic energy transfer

Ek = ½ × mass × velocity²

Gravitational potential energy

Energy stored due to height above Earth's surface

The equation for gravitational potential energy transfer

GPE = mass × GFS × height

Elastic potential energy

Energy stored when an object is stretched or compressed

The equation for elastic potential energy transfer

EPE = ½ × spring constant × extension²

Thermal (internal) energy

Internal energy from the kinetic and potential energy of particles; relates to temperature.

Chemical energy

Energy stored in chemical bonds between atoms.

Magnetic energy

Energy stored within a magnetic field.

Electrostatic energy

Energy stored in a system of electrical charges due to their positions.

Nuclear energy

Energy stored in the nucleus of an atom.

Mechanical energy transfer

Energy transferred by a force moving an object.

Electrical energy transfer

Energy transferred by charges moving through a potential difference.

Heating energy transfer

Energy transfer due to a temperature difference.

Radiation energy transfer

Energy transferred by electromagnetic waves (e.g., light, infrared).

The equation for work done

Work done = force × distance

Power

The rate at which energy is transferred at or work is done at

The equation for power

Power = work done / time

System

A single object or group of interacting objects where energy can be stored or moved.

Closed system

A system with no energy entering or leaving from external sources.

Conservation of energy

Energy cannot be created or destroyed; it can only be transferred, stored or dissipated.

Energy dissipation

Energy becomes spread into less useful forms or wasted stores (e.g., as heat).

Efficiency

Useful output energy divided by total input energy.

Friction

Resistance to motion between surfaces that converts some energy to heat.

Lubrication

Substances applied to reduce friction between moving surfaces.

How do lubricants reduce friction between moving parts?

They form a thin, slippery layer between the surfaces, which reduces direct contact between the bumps and rough parts of them

Insulation

A material that can reduce the transfer and flow of thermal energy.

How can insulation reduce thermal energy loss?

• It can trap tiny air pockets, reducing conduction

• Its structure blocks or slows air movement, reducing convection

• The material reflects heat, reducing radiation loss

Fossil fuels

Finite energy sources from fossilised plants/animals (coal, oil, natural gas).

Nuclear fuel

Uranium used in nuclear fission to release energy.

Renewable energy

Energy sources that replenish naturally and are inexhaustible over time.

Wind power

Energy from wind turning turbines to generate electricity.

Solar cells

Panels that convert sunlight directly into electricity; no moving parts.

Hydroelectric power

Electricity from moving water passing through turbines.

Tidal power

Turbines harness energy from tidal movement.

Wave power

Energy harvested from ocean waves via floating devices or devices on the seabed.

Geothermal energy

Heat from underground rocks driving turbines to generate electricity.

Biofuels

Organic material burned to generate electricity; renewable if resources regrow.

Base load

Minimum constant electricity demand met by reliable sources.

Peak demand

Sudden increases in electricity demand that require quick-start sources.

Impacts of fossil fuels: climate change

Burning fossil fuels releases CO₂, causing global warming, leading to rising sea levels and extreme weather.

Impacts of fossil fuels: air pollution

Fossil fuel combustion produces gases which react with water vapour to form acid rain.

Impacts of fossil fuels: Extraction damage

Mining coal or drilling for oil and gas can destroy habitats, pollute water sources, and cause soil erosion.

Impacts of nuclear energy: Nuclear waste

Nuclear plants produce highly reactive waste that remains hazardous for lifetimes, and disposal is complex and expensive.

Impacts of nuclear energy: Accident risk

Although rare, accidents can release radiation and contaminate the environment - e.g. Chernobyl

Impacts of renewable energy: Land usage

Large-scale projects like hydroelectric dams can destroy habitats and displace communities.

Impacts of renewable energy: Resource intensity

Manufacturing solar panels or batteries involves mining and chemical processes that have environmental footprints

Greenhouse effect

Warming caused by greenhouse gases trapping heat in the atmosphere.

What are some past trends in UK energy use?

The UK mainly used coal for electricity during the Industrial Revolution and early 20th century.

What are some present trends in UK energy use?

• Coal use has sharply dropped due to new environmental laws

• Renewables like wind and solar are fast growing

• Gas and nuclear energy still supplies a significant share of energy resources

What will some future trends in UK energy use be?

The UK is aiming for net zero carbon emissions by 2050, meaning the use of more renewable energy.