AQA Combined Physics 6.1 Flashcards
Revision for Paper 1 (44 cards)
What changes are involved in the way energy is stored when water is boiled in an electric kettle?
Electrical Energy - Thermal Energy
What changes are involved in the way energy is stored when an object falls?
Gravitational Potential Energy - Kinetic Energy
What changes are involved in the way energy is stored when an object is projected upwards?
Chemical Energy - Kinetic Energy - Gravitational Potential Energy
What is the conservation of energy principle?
Energy can be transferred usefully, stored or dissipated but never created or destroyed
What is power?
The rate at which energy is transferred / the rate at which work is done
Describe wind power and how it is used
Wind turbines are placed in exposed areas where rotating blades turn a generator producing electricity. They are non-polluting
What does the term renewable energy resource mean (and list them)?
Renewable energy resources can be replenished (will never run out) e.g. solar, wind, water waves, hydro-electricity, bio-fuel, tidal and geothermal
In terms of conduction across the material, what does an increased thermal conductivity of a material cause?
An increased thermal conductivity of material means a higher rate of energy transfer
What is conduction?
Conduction is the process where vibrating particles transfer energy to neighbouring particles (occurring mainly in solids)
How does insulation reduce unwanted energy transfers?
Insulation reduces the rate of energy transfer by heating
What equation is used to calculate the kinetic energy of a moving object?
Ek = 0.5 x m x v2
Kinetic energy = 0.5 x mass x speed2
What changes are involved in the way energy is stored when a vehicle slows down?
Kinetic Energy - Heat Energy
What changes are involved in the way energy is stored when a moving object hits an obstacle?
Kinetic Energy - Sound Energy / Thermal Energy
What happens to the energy transfer in a closed system?
There is no net change to the total energy
Lifting an object takes 10,000J - machine A can do this in 50s but machine B takes 100s. Which machine is more powerful?
Both machines transfer the same amount of energy, but machine A is more powerful: P = W / t
Machine A has a power of 200W ( 10000/50) whilst machine B has a power of 100W (10000/100)
What uses do we have for energy resources?
1) Transport
2) Electricity generation
3) Heating
What does the term non-renewable energy resource mean (and list them)?
Non-renewable energy resources will run out, e.g. coal, oil, natural gas and nuclear
What are the main energy resources available on Earth (including renewable and non-renewable)?
1) Fossil fuels
2) Nuclear fuel
3) Bio-fuel
4) Wind
5) Hydro-electricity
6) Geothermal
7) Tidal
8) Solar
9) Water waves
How do walls and the thermal conductivity of the material affect the rate of cooling in a building?
Thick walls made from a material with low thermal conductivity slows the rate of energy transfer (building remains warmer for longer)
What is convection?
Convection is the process where energetic particles move away from hotter regions to cooler ones (occurring in fluids)
List some examples of insulation
- Cavity wall insualtion (reduces convection)
- Loft insulation (reduces convection)
- Double-glazed windows (reduces convection)
- Draught excluders (reduces convection)
Describe bio-fuels and how they are used
Bio-fuels are made from plants and waste which are supposedly carbon neutral. Costs are high and bio-fuel crops reduce space for food crops
What energy resources are used for heating?
Natural gas is mainly used for heating, though coal and electric heaters are also used. Solar water heaters are also becoming more common
Describe water wave power and how it is used
Water wave power uses wave-powered turbines around the coast generating electricity
