Topic 3 ⚖️💥 Flashcards
In a closed conservation system with no energy transfers in or out, the total energy is?
Constant
What is the law of conservation?
Energy cannot be created or destroyed, only transferred from one form to another
What does higher thermal conductivity mean?
Greater rate of energy transfer
How is insulation helpful?
Reduces heat loss to surroundings
How is lubrication useful?
Reduces heat loss due to friction
The less waste energy means a more __________ appliance?
Efficient
What is waste energy?
Some supplied energy transformed into non-useful forms
Explain energy transfers in a vehicle braking.
KE —> heat energy by friction in the brakes
Explain energy transfers in a electric kettle?
Electrical energy —> heat energy
Explain the energy transfers in a bungee jumper.
As cord stretches, KE —> Elastic potential Energy, slowing down the jumper
Give a benefit of solar power?
Relatively cheap, can be used in remote areas, renewable.e
Give a disadvantage of solar power?
Only possible in daylight, inefficient, high initial cost
Give a benefit of wind power?
Cost effective and abundant source of energy
Give a disadvantage of wind power?
Restricted by wind speeds
Visual and sound pollution
Give a benefit of hydroelectricity?
Provide large quantities of energy in a short time
Give a disadvantage of hydroelectricity?
Affects water life
Only a limited number of suitable sites for water dams
Give a benefit of tidal power?
Renewable and predictable
High power output
Give a disadvantage of tidal power?
Relatively new so costly to install and maintain
Limited to site availability
Energy demand
Give a benefit of Bio Fuels?
Quickly and locally grown (renewable)
Less garbage in landfills
It is versatile
Give a disadvantage of bio fuels?
Needs a lot of land which could be used for food production
Not completely clean
Possible deforestation
Give a benefit of coal?
Cost effective and generation all the time
Large amounts of energy per kg of fuel
Give a disadvantage of coal?
Greenhouse emissions - carbon dioxide (global warming)
Causes sulphur dioxide (acid rain)
Give a benefit of gas?
Lower greenhouse emissions compared to other fossil fuels
Quick start up times allow for flexible generation
Give a disadvantage to gas?
Finite resource - limited supplies of gas
Gives of atmospheric pollutants
Give a benefit of nuclear fuel?
No greenhouse gases produces
Large amount of energy per kg of fuel
Give a disadvantage of nuclear fuels?
Harmful nuclear waste, must be stored for years
Risk of nuclear disasters (Chernobyl)
