energy Flashcards
What is work done?
Energy transferred
what is specific heat capacity
Amount of energy needed to raise the temperature of 1 kg of a substance by 1°
Practical to investigate specific heat capacity
• measure mass of block of copper
• wrap in insulating layer to reduce energy transferring to surroundings
• insert thermometer and record initial temperature
• set power supply to 10v and start stopwatch
• Record temperature every minute
• make sure ammeter doesn’t change
• Turn off after 10 minutes
• calculate specific heat capacity
in specific heat capacity practical, why does the block of material heat up?
current transfers energy electrically from power supply to heat his thermal energy store
What is power?
Rate of energy transfer
What is conduction?
Where vibrating particles transfer energy to neighbouring particles
what is convection?
Where energetic particles move from hotter to cooler regions
a what is thermal conductivity?
Measure of how quickly energy is transferred through material
two ways to reduce unwanted energy transfers
Lubrication – reduces frictional forces
Insulation – reduces energy wasted through heat
How can you investigate insulators?
• measure 300 mL of boiling water and pour into sealable container
• record initial temperature
• seal and leave for five minutes
• record final temperature
• restart with cool container
• repeat with different material
What is efficiency in energy transfers?
Wasting less energy in transfers
renewable energy resource for transport
bio fuel
For renewable energy sources
Wind – turbines
Solar – solar panel
Geothermal – underground
Hydroelectric – falling water
wave – wave turbines
tidal barrages – gravity
Pros and cons of biofuels
• carbon neutral, reliable
• Costly, deforestation
what are biofuels?
Renewable energy resources created from plants or animal dung
