Energy Flashcards
Recall some forms of Energy
Chemical, electrical, light, strain, thermal, sound, magnetic, kinetic, gravitational potential
State an example of Chemical energy
battery, food
State an example of electrical energy
lightbulb, switch
State an example of strain energy
elastic band
State an example of light energy
sun, lightbulb
State an example of gravity potential energy
holding up an object
State an example of thermal energy
sun, fire
State an example of sound energy
speaker, drill
State an example of magnetic energy
magnet
State an example of kinetic energy
bike, car
What is the the principle of conservation of energy?
‘The principle of conservation of energy states that energy cannot be created or destroyed merely transferred from one form to another
What is one Joule approximately the energy that is needed to do?
1J is approximately the energy needed to lift an apple vertically up 1m.
What does all energy eventually become?
Thermal energy
What is energy measured in?
joules - J
What do energy transfer diagrams show?
Energy in ——> device ——–> Energy out
The transfer of energy
Sankey Diagrams
look in book
What is renewable energy?
Renewable energy is defined as energy that is collected from resources that will never run out or which are naturally replenished within a human lifetime
What are the Advantages of Sunlight
Free
No GHG emitted.
Will not run out.
Reduce energy bills.
Develop a revenue stream.
What are the Advantages of wind
Free
No GHG emitted.
Will not run out.
Reduce energy bills.
Develop a revenue stream
What are the Advantages of Hydroelectric
Free electric
No GHG emitted.
Will not run out.
Reduce energy bills.
Develop a revenue stream.
Can control when power is
produced.
What are the Advantages of Tidal
Free electric
No GHG emitted.
Will not run out.
Reduce energy bills.
Develop a revenue stream.
Predictable power output.
What are the Advantages of Waves
Free electric
No GHG emitted.
Will not run out.
Develop a revenue stream.
Predictable power output
What are the Advantages of Geothermal heat
Free.
No GHG emissions.
Reduce bills.
Hot water can be
stored.
What are the Advantages of Woods
Will not run out (if replanted)
Can be stored for future use.
Can be grown locally
What are the Disadvantages of Sunlight
Intermittent
Low values near each pole.
What are the Disadvantages of Wind
Intermittent
High initial costs.
What are the Disadvantages of Hydroelectric
Need the correct topography of ground.
Huge initial investment.
What are the Disadvantages of Tidal
Need the correct topography of ground.
large initial investment.
What are the Disadvantages of Waves
Oil spills.
Habitat destruction.
Visual impact.
What are the Disadvantages of Wood
Overuse.
Does give out CO2.
What is efficiency?
Efficiency is a measure of how good a device is at changing energy from one form to another.
What are the Disadvantages of Geothermal heat
Expensive to set up.
Leaks into ground.
Can a device have 100% efficiency?
No, as all devices waste energy
Why is an energy efficient light bulb is more efficient than a filament bulb.
It wastes less energy and coverts a greater proportion of the energy supplied into light energy and not heat.
How is energy efficiency calculated?
Energy efficiency = Useful Output Energy/Total Input Energy eff = Eout/Ein
Useful and total energy is measured in Joules - J
Why is it important that electrical appliances display information about their energy efficiency.
It helps the consumer to identify which appliance will use the least energy and cost the least to run.
What are the units of energy efficiency?
It does not have any units, it is a number between 0-100 which can be converted into a percentage by multiplying by 100
