Physics Enery Resource and Electricity

How does an object become charged by friction

Electrons transfer between insulating materials when they are rubbed together

What happens to an object that gains electrons

It becomes negatively charged

What happens to an object that loses electrons

It becomes positively charged

What happens when two like charges are brought together

They repel

What happens when two unlike charges are brought together

They attract

Describe the energy transfers when an object falls

Gravitational energy to kinetic energy, with some energy to thermal energy

Describe the energy transfers when an object is lifted

Kinetic energy to gravitational energy

Describe the energy transfers when a stretched spring is released

Elastic energy to kinetic energy

Describe the energy transfers when a moving object is stopped by friction

Kinetic energy to thermal energy

Describe the energy transfers in a car moving using fuel

Chemical energy of fuel to kinetic energy of car, with some energy to thermal energy and sound

Describe the energy transfers in an electric motor

Electrical energy to kinetic energy, with some energy to thermal energy and sound

Describe the energy transfers in a filament lamp

Electrical energy to light and thermal energy

Describe the energy transfers in an electric heater

Electrical energy to thermal energy

Describe the energy transfers in a loudspeaker

Electrical energy to sound and thermal energy

What is the principle of conservation of energy

Energy cannot be created or destroyed, only transferred

What is a renewable energy resource

An energy resource that is naturally replenished

What is a non-renewable energy resource

An energy resource that is not replaced as fast as it is used

Why are fossil fuels non-renewable

They take millions of years to form

What are the renewable energy resources in the specification

Wind, water, geothermal, solar heating and solar cells

What are the non-renewable energy resources in the specification

Fossil fuels and nuclear power

Describe the energy transfers in wind electricity generation

Kinetic energy of moving air to kinetic energy of turbine to electrical energy of generator

Why is wind power renewable

Wind is naturally replenished

What is an advantage of wind power

No fuel is burned

What is a disadvantage of wind power

Wind is intermittent

Describe the energy transfers in hydroelectric electricity generation

Gravitational energy of water to kinetic energy of moving water to kinetic energy of turbine to electrical energy of generator

Why is hydroelectric power renewable

The water cycle continually replenishes the water

What is an advantage of hydroelectric power

It is renewable and reliable when water is stored

What is a disadvantage of hydroelectric power

Dams can flood land and damage habitats

Describe the energy transfers in geothermal electricity generation

Thermal energy of hot rocks to thermal energy of water to kinetic energy of steam to kinetic energy of turbine to electrical energy of generator

Cold water is pumped into hot dry rock. What happens to the energy

Thermal energy of hot rocks to thermal energy of water

What happens when the heated water produces steam

Thermal energy of water to kinetic energy of steam

What happens when the steam turns the turbine

Kinetic energy of steam to kinetic energy of turbine

What happens when the turbine turns the generator

Kinetic energy of turbine to electrical energy of generator

Why is geothermal energy renewable

The Earth's internal thermal energy is continually replenished

What is an advantage of geothermal energy

It is renewable and reliable

What is a disadvantage of geothermal energy

Suitable locations are limited

Describe the energy transfers in solar heating

Radiation from the Sun to thermal energy of material or fluid

Why is solar heating renewable

Solar energy is continually replenished

What is an advantage of solar heating

No fuel is burned

What is a disadvantage of solar heating

It depends on sunlight

Describe the energy transfer in a solar cell

Radiation from the Sun to electrical energy

What is an advantage of solar cells

No fuel is burned

What is a disadvantage of solar cells

Output depends on sunlight

Describe the energy transfers in a fossil-fuel power station

Chemical energy of fuel to thermal energy to kinetic energy of steam to kinetic energy of turbine to electrical energy of generator

What happens when fossil fuel is burned

Chemical energy of fuel to thermal energy

What is an advantage of fossil-fuel power stations

Reliable and controllable electricity generation

What is a disadvantage of fossil fuels

They release carbon dioxide and are non-renewable

Describe the energy transfers in a nuclear power station

Nuclear energy to thermal energy to kinetic energy of steam to kinetic energy of turbine to electrical energy of generator

What is an advantage of nuclear power

Large amounts of electricity with low carbon dioxide emissions during operation

What is a disadvantage of nuclear power

Radioactive waste is produced

Why is nuclear power non-renewable

Nuclear fuel is finite

Why can renewable energy resources be intermittent

Their availability depends on changing natural conditions

Why is a mixture of energy resources used

Different resources have different advantages, disadvantages and reliability

What is conduction

Thermal energy transferred through a material by particle collisions

What is convection

Thermal energy transferred by the movement of a fluid

Explain convection in a fluid

Hot fluid becomes less dense and rises while cooler fluid sinks

What is thermal radiation

Energy transferred by infrared radiation

Which surfaces are good emitters and absorbers of thermal radiation

Dull black surfaces

Which surfaces are poor emitters and absorbers of thermal radiation

Shiny light-coloured surfaces

How can unwanted thermal energy transfer be reduced

Use insulation

How is energy represented in a Sankey diagram

Arrow width represents the amount of energy transferred

What does a Sankey diagram show

Useful and wasted energy transfers

What is efficiency

Useful energy output divided by total energy input multiplied by 100%

What is power

The rate of transfer of energy

What is work done

Energy transferred when a force moves an object

What is the unit of energy

Joule

What is the unit of power

Watt