Studied by 2 people
What can energy be stored as?
Energy can be stored as kinetic, gravitational potential, chemical, elastic, nuclear, electrostatic and thermal energy
How is energy transferred by mechanical working?
When a force acts on an object e.g pulling or pushing
How is energy transferred by electrical working?
A charge moving through a potential difference
Heating by particles
Energy is transferred from a hotter object to a colder one
Heating by radiation
Energy is transferred by electromagnetic waves
What is the principle of the conservation of energy?
Energy can not be created nor destroyed, only transferred.
Formula for kinetic energy
Kinetic energy = ½ x mass (kg) x velocity squared (m/s)
Formula for gravitational energy
Gravitational energy = mass (kg) x g (N/kg) x Change in height (meters)
What is mechanical or electrical work done equal to
The energy transferred
Work done equation
Work done (J or Newton meters) = Force (N) x Distance (m)
How can useful energy be obtained by burning fossil fuels or biofuels?
When fossil fuels of biofuels are burnt, energy is released from their chemical stores which heats up a boiler a turns water into steam. The steam is then used to spin a turbine which powers a generator
How can useful energy be obtained by nuclear fuel?
Nuclear fuel is used to create useful energy by undergoing nuclear fission reactions, which creates heat which heats up a boiler which turns water into steam. The steam is used to spin a turbine and power a generator
How can useful energy be obtained by energy stored in waves or tides?
The rise and fall of waves or tides can be used to spin a turbine and power a generator
How can useful energy be obtained by water behind hydroelectric dams?
Water is stored behind a dam in its gravitational potential store. This can be transferred to kinetic energy if the water is allowed to flow down the slope, which spins a turbine which powers a generator
How can useful energy be obtained by geothermal sources?
Cold water is heated by rocks underground and turned into steam which spins a turbine which powers a generator
How can useful energy be obtained by light from the sun?
Solar cells transfer energy from sunlight electrically producing a current and therefore generating electricity
How can useful energy be obtained by light and heat from the sun?
Solar panels transfer energy from the sun to thermal energy which heats up water turning it into steam, which spins a turbine and powers a generator
advantages and disadvantages of fossil fuels in terms of renewability, availability, reliability, scale and environmental impact
Non renewable, readily available on a daily basis, very reliable, Large scale, and extremely bad for the environment
advantages and disadvantages of biofuels in terms of renewability, availability, reliability, scale and environmental impact
Renewable, moderate availability, reliable, large or small scale, produces CO2
advantages and disadvantages of nuclear fission in terms of renewability, availability, reliability, scale and environmental impact
Non renewable, readily available on a daily basis, reliable, very large scale, doesn’t produce CO2 however accidents can happen
advantages and disadvantages of tidal in terms of renewability, availability, reliability, scale and environmental impact
Renewable, only stretches of coast are suitable, reliable, very large or small scale, no CO2 is produced but damages habitats
advantages and disadvantages of wave in terms of renewability, availability, reliability, scale and environmental impact
Renewable, not all coasts have powerful and reliable waves, not reliable, small scale, does not produce CO2
advantages and disadvantages of hydroelectric in terms of renewability, availability, reliability, scale and environmental impact
Renewable, only a few rivers are suitable for large dams, reliable, Big or small scale, no CO2 produced but does damage habitats
advantages and disadvantages of geothermal in terms of renewability, availability, reliability, scale and environmental impact
Renewable, limited to areas with geological fault, reliable, large scale, no CO2 produced
advantages and disadvantages of wind in terms of renewability, availability, reliability, scale and environmental impact
Renewable. not all areas have powerful enough wind, not reliable, large or small scale, no CO2 but have been bird strikes
advantages and disadvantages of solar (electric and heating) in terms of renewability, availability, reliability, scale and environmental impact
Renewable, varies according to day and night pattern for availability and reliability, small scale, no CO2 produced
All of our sources of energy originate to the sun apart from?
Nuclear, Geothermal and Tidal
How is energy released in the Sun?
Nuclear fusion
Is research being carried out to investigate how energy released by nuclear fusion can be used to produce electricity?
Yes
Equation for efficiency?
Efficiency = useful energy or power input/total energy or power input x 100
Equation for power (1)
Power (W) = work done (J)/time (s)
Equation for power (2)
Power (W) = energy transferred (J)/t (s)
Note 
Flashcard (95)