P P1 - Energy Flashcards
What is a closed system?
A closed system is when energy cannot escape, so there is no change in the total energy in the system
What is an open system?
An open system is when energy can dissipate
How do you calculate work done?
Work done = force x distance
What does it mean when work is done?
Work is done when an object moves and energy is transferred
How can you reduce friction?
Friction can be reduced by using wheels, applying lubrication
How can you reduce air resistance?
Air resistance can be reduced by travelling slowly and streamlining
What is the law of conservation of energy?
The law of conservation energy is when energy can be transferred, but not created or destroyed
What are ways that wasted energy can be reduced?
Wasted energy can be reduced by insulation, streamlining, lubrication of moving parts
What happens to wasted energy?
Wasted energy dissipates into the surroundings as thermal energy
How can efficiency be increased?
Efficiency can be increased by using machines
What is specific heat capacity?
Specific heat capacity is the amount of energy required to raise 1kg of a substance by 1 degree
What does specific heat capacity depend on?
Specific heat capacity depends on the mass of a substance, what the substance is, and the energy put into the system
How do you calculate the change in thermal energy?
Change in thermal energy = mass x specific heat capacity x temperature change
What are the ways in which energy can be transferred?
Energy can be transferred through light, sound, electricity, thermal, kinetic
What is kinetic energy?
Kinetic energy is the energy stored by a moving object
What is elastic potential energy?
Elastic potential energy is the energy stored in a stretched spring, elastic band
What is gravitational potential energy?
Gravitational potential energy is the energy gained by an object when raised above the ground
How do you calculate kinetic energy?
Kinetic energy = 1/2 x mass x velocity (squared)
How do calculate elastic potential energy?
Elastic potential energy = 1/2 x spring constant x extension (squared)
How do you calculate gravitational potential energy?
Gravitational potential energy = mass x gravitational field strength x height
What is a non-renewable energy resource?
A non-renewable energy resource is a resource that will run out
What is a renewable energy resource?
A renewable energy resource is a resource that will never run out
What are examples of non-renewable energy resources?
Examples of non-renewable energy resources are fossil fuels such as coal, oil and gas
What are examples of renewable energy resources?
Renewable energy resources include solar, tidal, wave, wind, geothermal, biofuel, hydroelectric
How much renewable energy makes up energy consumption?
Renewable energy makes up only 20% of energy consumption
What three human activities use the most fuel?
Transport, heating (gas, radiators), and electricity
What is the process of generating electricity in power stations?
In power stations, they generate electricity by:
- burning the fuel to release thermal energy
- boil water into steam
- the steam turns turbines
- the turbine turns generator
- the generator induces voltage
How does the national grid transport electricity across the UK?
Power station > step-up transformer > pylons (electricity towers) > step-down stransformer > houses, factories
What are the positives of using fossil fuels?
The positives of using fossil fuels is that it provides most of the UK energy, it has large reserves, cheap to extract, used in transport, heating and making electricity, it is easy to transport
What are the negatives of using fossil fuels?
The negatives of using fossil fuels is that it is non-renewable, releases sulfur and carbon dioxide, can cause acid rain, contributes to global warming, environmental damage if oil spills
What are the positives of using nuclear energy?
The positive of using nuclear energy is that it has no greenhouse gases and that lots of energy is produced from small amounts of fuel
What are the negatives of using nuclear energy?
The negative of using nuclear energy is that it is non-renewable, there are dangers of radioactive materials being released into the air or water, nuclear sites require lots of security, start-up costs are high, toxic waste needs to be carefully stored
What are the positives of using biofuel?
The positives of using biofuel are that it is renewable, the plants growing removes carbon dioxide and they are ‘carbon neutral’
What are the negatives of using biofuel?
The negatives of using biofuel include needing large areas of lang in order to grow fuel crops, habits are destroyed and food is not grown, emitting CO2 when burnt
What are the positives of using tidal energy?
The positives of using tidal energy are that it is renewable, predictable due to the consistency of tides, no greenhouse gases are produced
What are the negatives of using tidal energy?
The negatives of using tidal energy include high expenses to set up, altering habitats, causes problems for ships and boats
What are the positives of using wave energy?
The positives of using wave energy are that it is renewable and there are no waste products
What are the negatives of using wave energy?
The negatives of using wave energy are that it can be unreliable as it depends on wave output
What are the positives of using hydroelectricity?
The positives of using hydroelectricity are that it is renewable and there are no waste products
What are the negatives of using hydroelectricity?
The negatives of using hydroelectricity are that habitats are destroyed
What are the positives of wind energy?
The positives of using wind energy are that it is renewable and there are no waste products
What are the negatives of wind energy?
The negatives of using wind energy is that is it unreliable as the wind varies, there is visual and noise pollution, it is dangerous to migrating birds
What are the positives of using solar energy?
The positives of using solar energy are that it is renewable and there are no waste products
What are the negatives of using solar energy?
The negatives of using solar energy are that it is expensive and unreliable due to varying light intensity
What are the positives of using geothermal energy?
The positives of using geothermal energy are that it is renewable and clean, and no greenhouse gases are produced
What are the negatives of using geothermal energy?
The negatives of using geothermal energy are that it is limited to a small number of countries, and geothermal power stations cause earthquake tremours
