Section 4 - Energy Resources and Energy Transfer Flashcards
What is the principle of the conservation of energy?
Energy can never be created nor destroyed - it’s only ever transferred from one form to another
e. g. chemical energy in food to kinetic energy in animals
e. g. electrical energy to light energy in lamps
What is the equation for EFFICIENCY?
Efficiency = Useful Energy Output / Total Energy Input
What does it mean if an object is efficient?
A lot of its released energy is in a useful form
What are the three ways in which heat is transferred?
Conduction, Convection and Radiation
What is conduction?
Conduction is when energy is passed from one particle to another via contact.
What is convection?
Convection is when particles with energy rises. The space that they leave is filled by other particles. If the source of energy continues, these new particles will also gain energy. Then, they will rise and the process is repeated.
What is radiation?
Radiation is when heat is transferred as infrared waves. These waves can travel through space and be conducted or reflected
What role does convection have in everyday life?
A radiator in a room will be able to heat a whole room, as hot air will rise away from it creating a current of cool air to be heated
How can we reduce energy transfers from buildings and the human body?
Insulation can be used to reduce heat transfer.
For example, a house can have double glazed windows and thick curtains
What is the equation for WORK DONE?
Work Done = Force x Distance Moved
What does work done equal to?
Work Done is equal to Energy Transferred
What is the equation for GRAVITATIONAL POTENTIAL ENERGY?
GPE = mass x gravitational field strength x height
What is the equation for KINETIC ENERGY?
KE = 1/2 x mass x velocity^2
How is kinetic energy and gravitational potential energy linked?
When an object falls, it reduces gravitational potential energy and gains kinetic energy.
Kinetic Energy Gained = GPE Lost
What is power?
Power is the rate of transfer of energy or the rate of doing work
What is the equation for POWER?
Power = Work Done / Time Taken
Describe the energy transfers involved in generating electricity using wind
Kinetic energy (wind) turns a turbine, which turns a generator. This produces electrical energy.
Describe the energy transfers involved in generating electricity using water
Kinetic energy (water) turns a turbine, which turns a generator. This produces electrical energy.
Describe the energy transfers involved in generating electricity using geothermal resources
Thermal energy heats water. The water turns into steam and the steam turns a turbine, which then has kinetic energy. The turbine turns a generator, which produces electrical energy
Describe the energy transfers involved in generating electricity using solar heating systems
Solar heating systems convert light energy from the sun to thermal energy in water (it heats it up)
Describe the energy transfers involved in generating electricity using solar cells
Solar cells convert light energy from the sun into electrical energy
Describe the energy transfers involved in generating electricity using fossil fuels
Chemical energy is burnt to form heat energy. This energy into heat energy in water. This turns into kinetic energy in a turbine, which turns into electrical energy in a generator.
Describe the energy transfers involved in generating electricity using nuclear power
Kinetic energy in uranium is converted to heat energy in water. This heat energy turns a turbine (KE), which produces electrical energy in a generator
