(Done) Energy (Paper 1) Flashcards
Energy stores (8)
- Thermal
- Kinetic
- Gravitational Potential
- Elastic Potential
- Chemical
- Magnetic
- Electrostatic
- Nuclear
Energy Pathways (4)
- Mechanical
- Heating
- Electrical
- Radiation
What is a system
- A single object or a group of objects that you are interested in
What happens when a system changes
- Energy is transferred into or away from the system, between different objects in the system or different types of energy stores
What are closed systems
- Systems where no matter or energy can enter or exit, the net change in the total energy is all ways zero
When is “Work Done”
- When current flows
- By a force moving an object
Kinetic energy calculation
- E(k) = 1/2 x mass x velocity^2
When is energy in the kinetic energy store
- Whenever an object is moving
Gravitational potential energy calculation
- E(p) = Mass x Gravitational field strength x Height
When is energy in the gravitational energy store
- When an object is lifted off the ground
Elastic potential energy calculation
- E(e) = 1/2 x Spring Constant x extension^2
When can the elastic potential energy calculation not be applied to a stretched object
- When the limit of proportionality is exceeded
When is energy in the elastic potential energy store
- When an object is stretched or squashed
Define specific heat capacity
- The amount of energy needed to raise 1 Kg of substance by 1 degree
Specific heat capacity equation
- Change in thermal energy = Mass x Specific heat capacity x Temperature change
What is the conservation of energy principle
- Energy can be transferred usefully, stored or dissipated but cannot be created or destroyed
What is the power calculation
- Power = Energy Transferred / Time
- Power = Work Done / Time
Define conduction
- The process where vibrating particles transfer energy to neighboring particles
Why does conduction happen
- As the particles within a solid gain temperature, they gain energy
- This causes them to vibrate more and collide with each other
- As the particles collide with each other, the energy from the collision is transferred to the neighboring particles
Define thermal conductivity
- A measure of how quickly energy is transferred through a material through conduction
Define convection
- Where energetic particles move away from hotter to cooler regions
In what state do conduction and convection mainly occur
- Conduction - Solids
- Convection - Liquids and Gasses
What happens in convection
- Energy transferred by heating is shared across the particles’ kinetic energy store
- Due to the particles within a liquid or gas being able to move, when a region is heated, the heated particles move about more and the space between the particles increase
- This causes the density of the heated area to decrease and since liquids and gasses are able to flow, the less dense area will rise above the denser area
What can be used to reduce friction
- Lubricants (Liquids used to coat)
What can be used to reduce the rate of energy transferred by heating
- Insulation (Materials with a low thermal conductivity)
Efficiency calculation
- Efficiency = Useful output energy / Total input energy
- Efficiency = Useful power output / Total power input
Non-renewable energy sources
- Coal
- Oil
- Natural Gas
- Nuclear
Renewable energy sources (7)
- Solar
- Wind
- Water waves
- Hydro electricity
- Bio-Fuel
- Tides
- Geothermal
Advantages and disadvantages of wind power
Advantages
- No pollution
- No permanent damage to the landscape
Disadvantages
- Fill up the landscape
- High initial costs
- Can be quite noisy
How do wind turbines work
- Turbines are placed in large open areas such as coasts or moors
- There is a generator inside the turbine that is rotated by the fans being moved by the wind
Advantages (1) and disadvantages (3) of solar cells
Advantages
- No pollution
Disadvantages
- High initial costs
- Requires sun
- Can’t increase power output with high demand
Advantages (3) and disadvantages (2) of geothermal power
Advantages
- Free
- Reliable
- Little damage to the environment
Disadvantages
- Not many suitable locations
- High initial cost compared to the energy it produces
Advantages (3) and Disadvantages (2) of Hydro-electric power
Advantages
- No pollution
- can provide an immediate response to an increase in demand
- No fuel costs and minimal running costs
Disadvantages
- High initial costs
- impact on the environment due to flooding a valley
Advantages (1) and disadvantages (3) of wave power
Advantages
- No pollution
Disadvantages
- High initial costs
- Unreliable
- Damage to seabed and marine habitats
Tidal barrage advantages (4) and disadvantages (2)
Advantages
- Reliable
- No pollution
- No fuel costs
- Minimal running costs
Disadvantages
- High initial costs
- Preventing free access for boats
Bio-Fuel advantages (1) and disadvantages (2)
Advantages
- Reliable
Disadvantages
- High costs
- Cannot respond to sudden increases in demand
Advantages (3) and disadvantages (2) of fossil fuels
Advantages
- Reliable
- Can respond to changes in demand
- Cheap
Disadvantages
- Finite
- Causes pollution
Consequences of fossil fuels (5)
- Burning coal and oil releases sulfur dioxide which causes acid rain
- Coal mining messes up the landscape
- Oil spillages cause serious environmental problems
- Nuclear waste is difficult to dispose of
- Nuclear power has risk of major catastrophe
