Energy Flashcards
What are the 8 energy stores?
Chemical energy Elastic potential energy Gravitational potential energy Magnetic energy Electrostatic energy Nuclear Energy Thermal energy Kinetic energy
What energy transfer occurs when a ball falls?
gravitational potential to kinetic
What is the equation used for finding the energy in an objects kinetic energy store?
Ek = 0.5 x m x v^2
kinetic energy = half x mass x volume squared
What is the equation used for finding the energy in an objects gravitational potential energy store?
Ep = mgh
Gravitational potential energy = mass x gravitational field strength x height
what is gravitational field strength measured in?
N/kg (Newtons per kilogram)
What is the definition of specific heat capacity?
How much energy is needed to increase the heat of 1kg of material by 1 degrees
What is the equation used to find the energy in an elastic potential energy store?
Ee = 0.5 x k x e^2
Elastic potential energy = half x spring constant x extension squared
What is springs constant measured in?
N/m (Newtons per meter)
What equation links energy transferred to specific heat capacity?
△E = mc△0
Change in thermal energy = mass x specific heat capacity x temperature change
What is conduction
Conduction is when particles vibrate more and collide with each other due to an object being heated and energy transferred to its kinetic energy stores of its particles. During these collisions energy is transferred between particles’ kinetic energy stores
Name three ways you can prevent energy losses through heating
- Have thick walls made from material with a low thermal conductivity
- Double-glazed windows
- Loft insulation
How does cavity wall insulation reduce the amount of energy transferred out of a house
Cavity walls are made up of an inner and an outer wall with a gap in the middle. The air gap reduces the amount of energy transferred by conduction through the walls.
What are the two ways of calculating effciency for an energy transfer?
effciency = useful output energy transfer ÷ total input energy transfer
or
efficiency = useful power output ÷ total power input
What is the difference between renewable and non-renewable energy?
Renewable energy is energy that will never run out eg. Solar and wind power and non-renewable energy is energy that will eventually run out eg. coal and natural gas
Name the 8 renewable energy sources
- Wind
- Solar
- Geothermal
- Hydro Electric
- Wave
- Tidal
- Nuclear
- Biofuel
Explain wind power
- Wind turbines get placed in exposed places
- kinetic energy is transferred from the wind and as the blades rotate, the generator inside the turbine produces electricity
- no permanent environmental damage, no fuel costs, minimal running costs
- view and noise pollution, impossible to increase supply, rely on the weather
Explain solar cells
- Solar cells generate electric currents directly from sunlight
- no pollution, very reliable in sunny countries, cost-effective, very low running costs
- can’t increase the power output
Explain geothermal power
- The slow decay of various radioactive elements eg Uranium inside the Earth
- free energy, reliable, very little damage to the environment, can generate electrivity or heat buildings directly
- aren’t many suitable locations for power plants, high cost for building power plant
Explain Hydro-electric power
- The flooding of a valley (by building a big dam), water is allowed out through turbines
- no pollution, can provide an immediate response to increased demand for elc, no fuel costs, minimal running costs, useful for small scale
- big environmental impacts (flooding = rotting vegetation = methane and co2), ugly when they dry up, high initial costs
Explain wave power
- Lots o small wave-powered turbines around the coast, moving turbines connected to a generator
- no pollution, no fuel costs, minimal running costs
- disturbs seabed and habitats of marine animals, hazard to boats, fairly unreliable (waves die out when wind drops), high initial costs
Explain Tidal Barrages
- big dams across river estuaries with turbines in them
- the tide comes in and fills the estuary, water is allowed out through turbines
- no pollution, pretty reliable, no fuel costs, minimal running costs, generate a significant amount of energy
- prevents free access by boats, alters habitat of wildlife, ugly, height of tide varies, high initial costs
Explain bio-fuels
- created from either animal dung or plants proucts
- fairly reliable, supposedly carbon nuetral
- can’t respond to immediate energy demands, very expensive, some areas have had large areas of forest cleared for bio-fuels to be grown, resulted in species loosing their ntural habitats and increases methane nd o2 emissions
