P1 - Energy

What is the unit for energy?

Joules, J

What are the 8 energy stores?

Chemical Elastic Magnetic Electrostatic Nuclear Thermal Kinetic Gravitational

What are the 4 energy transfers?

Mechanical, heating, radiation and electrical

Thermal: Is this an example of a store or a transfer?

Store

Heating: Is this an example of a store or a transfer?

Transfer

Electrical: Is this an example of a store or a transfer?

Transfer

Electrostatic: Is this an example of a store or a transfer?

Store

What type of energy is stored in moving objects?

Kinetic

What type of energy is stored in objects that have been stretched or squashed?

Elastic

What type of energy is stored in objects that have been lifted above ground?

Gravitational potential energy (GPE)

What type of energy is stored in batteries, food and drink?

Chemical

What is the equation for gravitational potential energy?

GPE = mass x height x gravitational field strength

What is the equation for kinetic energy?

KE = 0.5 x mass x velocity²

What is the correct unit for mass?

Kilograms, kg

What is the correct unit for extension or height?

Metres, m

How is energy transferred from the house mains to a hairdryer?

Electrical transfer

What is the useful transfer from a filament lamp?

Radiation (light)

What is the wasted transfer from a filament lamp?

Heating

What is the conservation of energy law?

energy cannot be created or destroyed, only stored, transferred usefully or dissipated

What is a closed system?

A collection of objects where neither energy nor matter can leave

What is the equation for power? (2)

Power = energy ÷ time

Power = work done ÷ time

What is the definition of power?

The rate of energy transfer or work done

What is the unit for power?

Watts, W

What are the two ways to calculate efficiency?

Efficiency = useful energy output ÷ total energy input

Efficiency = useful power output ÷ total power input

Can devices be 100 % efficient?

No. Energy is always wasted

What are two ways to reduce unwanted energy transfers?

Lubrication

Thermal insulation

How can lubrication reduce unwanted energy transfers? (2)

Lubrication reduces frictional forces between surfaces of objects that are being rubbed together

This reduces energy loss by heating

How can thermal insulation reduce unwanted energy transfers? (3)

Thick walls made from a material with low thermal conductivity slows the rate of energy transfer

Cavity walls have an inner and outer wall with an air gap in the middle

The gap slows the rate of energy transfer as air particles have low conductivity

[𝗛𝗶𝗴𝗵𝗲𝗿 𝗧𝗶𝗲𝗿] How can the efficiency of an energy transfer be increased?

By reducing the amount of energy wasted (e.g. by lubrication or thermal insulation)

What is specific heat capacity?

The amount of energy required to raise the temperature of 1 kg of a substance by 1ºC.

Describe how you would find the specific heat capacity of a solid block of a material (7)

Measure the block's mass (m), using a balance

Measure the initial temperature of the block, using a thermometer

Put a heater into a hole in the block

Measure the energy supplied to the block (ΔE), using a joulemeter

Measure the final temperature of the block, using a thermometer

Calculate the temperature change (ΔT) from the difference between the final and initial temperatures

Calculate the specific heat capacity using c = ΔE / m ΔT

What are the main energy resources available for use on Earth? (7)

Fossil fuels (coal, oil, natural gas)

nuclear fuel

biofuel

wind

water (hydroelectric, waves, tides)

solar

geothermal

What is the definition for a renewable resource?

A resource that can be replenished as it is being used up

What is the definition for a non-renewable resource?

A resource that is not replenished as it is used up

Which energy resources are non-renewable?

Fossil fuels and nuclear fuels

Nuclear: Is this an example of a renewable or non-renewable resource?

Non-renewable

Fossil fuels: Is this an example of a renewable or non-renewable resource?

Non-renewable

Hydroelectric power: Is this an example of a renewable or non-renewable resource?

Renewable

Solar: Is this an example of a renewable or non-renewable resource?

Renewable

Wind: Is this an example of a renewable or non-renewable resource?

Renewable

Geothermal: Is this an example of a renewable or non-renewable resource?

Renewable

Which energy resource generates the most power?

Nuclear fuels

Which energy resources are unreliable due to weather?

Wind and solar

Which non-renewable energy resource produces carbon dioxide?

Fossil fuels

What chemical environmental issues are caused by energy resources? (3)

Fossil fuels: produce CO₂ which causes global warming

Biofuels: also produce CO₂ when burnt (but this can be off-set by planting more)

Nuclear fuels: produce radioactive waste which needs to be safely disposed of

What environmental issues are caused by renewable energy resources? (3)

Hydroelectric: reservoirs require the flooding of large areas of land

Solar: large area of ground are covered (cannot be used for crops)

Wind, tidal: can affect the habitats they are in

Why do we use more non-renewable than renewable energy resources? (2)

Non-renewable energy resources are more reliable

We currently have more power stations and vehicles that are designed for non-renewable energy resources

Why do people want to use renewable energy resources? (2)

Fossil fuels are damaging to the environment

People and governments want to get used to using renewables before non-renewables eventually run out

How does reliability limit the use of renewables? (2)

Renewable energy resources are often unreliable or unable to increase their power output on demand

This means either having to use a combination of power plants (expensive) or researching ways to improve reliability and cost

How do political considerations limit the use of renewable energy resources? (2)

Scientists can only advise people - they don't have the power to change the behavior of the governments or companies

Governments will consider other factors, such as trade deals and jobs, when making decisions

How do social considerations limit the use of renewable energy resources?

Changing to use more renewable energy resources may cause people to lose their jobs, or have to move house

How do ethical considerations limit the use of renewable energy resources? (2)

Behaving ethically means trying to do the right thing for people

There are disadvantages caused by renewable energy resources which may make people's lives worse