Energy Flashcards
(30 cards)
How is energy transferred?
Energy is transferred mechanically, electrically, by heating or by radiation
What is the kinetic energy equation?
1/2 mv^2
1/2 x mass x speed^2
What is energy measured in?
Joules
What is the gravitational potential energy equation?
Mgh
Mass x gravitation field strength x height
What is the elastic potential energy equation?
1/2 x spring constant x extension^2
1/2ke^2
What is the conservation of energy principle?
Energy can be transferred usefully, stored or dissipated, but can never be created or destroyed
There are two equations for power, name both of them.
Power = Energy transferred / time (s) Power = Work done / time (s)
What is conduction and where does it occur?
Conduction is the process where vibrating particles transfer energy to neighbouring particles. Mainly occur in solids
What is convection and where does it occur
Convection is where energetic particles move away from hotter to cooler regions. Occur in liquids and gas
What do radiators do?
They create convection currents. Energy is transferred from the radiator to the nearby air particles by conduction. Air near the radiator gets warm, warm air rises, cool air sinks to replace rising air
Name the ways to reduce unwanted energy transfer.
Lubrication
Insulation
Name the ways you can insulate the house and describe them.
Cavity walls - made up of inner and outer wall with air in the gap, the air gal reduces the amount of energy transferred by conduction through the wall
Double glazed windows - work in the same way as cavity walls
Loft insulation - reduce convection currents being made in the loft
Draught excluders - near doors and windows reduce energy transfers by convection
What is the efficiency equation?
Efficiency = useful energy/total energy
Name non renewable energy resources.
Coal Oil Natural gas Petrol/diesel Electric heaters
Name renewable resources
Sun Wind Water waves Hydro - electricity Bio - fuel Tides Geothermal
Describe what wind power is and it’s advantages and disadvantages.
Wind power is wind turbines the rotating blades turn the generator and produce electricity. They can spoil the view, they can be noisy, you need a lot of wind turbines. Advantages are there are no permanent damages to landscape, no fuel costs.
What do solar cells do?
Solar cells generates electric currents directly from the sunlight.
Disadvantages and advantages of solar cells.
Advantages - no environmental damage, energy is free after they have been fixed
Disadvantages - need the country to have sun and costs alot
What is geothermal power?
The source of much of the energy is the slow decay of various radioactive elements deep inside the earth. Energy comes from underground thermal energy stores and is very reliable.
Explain why the UK plans to use more renewable energy resources in the future.
We know fossil fuels is very damaging to environment. This makes people want to use more renewable energy resource that affect the environment less
Non renewable resources will run out one day better to get used to it before the day comes.
Currently we still depend on fossil fuels, but what do we use fossil fuels on?
Most of our electricity is produced using fossil fuels and from nuclear powers. We burn fossil fuels on oil which is used for fuel cars, and gas is used to heat homes and cook food etc.
The use of renewable resources is being limited by what?
Reliability
Money
Politics
What does hydro electric power require?
Usually requires the flooding of a valley by building a big dam
What are the disadvantages of hydro electric power?
Possible rotting of vegetation
Release of methane and carbon dioxide
Loss of habitat