P1 - Energy Flashcards
4 methods of energy transfer
Mechanic
Electrical
Heat
Radiation
Name up to 5 types of energy
Magnetic Electrostatic Kinetic Gravitational potential Nuclear
Formula for energy using specific heat capacity
Energy(J)= mass(kg)xSHC(J/KG*C)xchange in temp
What is a closed system
No energy or matter can enter/leave
What happens when energy in the thermal energy store increases
It heats and is transferred electrically
Formula for kinetic energy
Kinetic energy(J)= 0.5(massxspeed^2)
What happens to an object as gravitational potential energy decreases
Kinetic energy increase if no air resistance
If air resistance energy is transferred to other stores
What does stretching/squishing do to the gravitational potential energy store
Increases if below limit of proportionality
What is specific heat capacity
Energy to increase 1kg by 1 degree
What does conservation of energy rule state
Energy can only be transferred or dissipated not:
Created or destroyed
How can you investigate specific heat capacity?
Metal block with 2 holes (e.g copper)
Measure mass + wrap undulation & insert immersion heater + thermometer
Measure initial temp
Use volt and ammeter
Set voltage to 10V + turn on power supply
Time it until 1degree change
What is power
The rate of work done/energy transfer
Power 1 equation
Power(W)= Energy transferred(J)/time(s)
Power 2 equation
Power(W)= Work some(J)/time(s)
How would a more powerful engine impact the cars travel time
Decrease, it can transfer the same energy in less time
2 ways to reduce unwanted energy transfers
- Lubricant (less friction)
- Heat with more conduction/convection
- Insulation
What increases conduction/convection
Heat = more kinetic = vibrate = collisions = more energy transferred
If particles are free to move ….
They have more space = lower density
What is convection
Liquids and gas flow so less dense will rise above denser and cooler regions
4 examples of thermal insulation
- Cavity walls (less c&c)
- Loft insulation (less convection)
- Double glazing (less conduction)
- Fraught excluders (reduce convection)
The purpose of insulation
Reduce the rate of energy transfer
Example of finite energy resources
Nuclear, fossil
What is a common use of energy resources
Transport
Petrol, diesel, coal, pure bio-fuels
Give a renewable and non renewable resource for heating
Natural gas (water and radiators) Geothermal pump for buildings
Advantages of hydroelectricity
No pollution
Supply and demand
Reliable unless drought
Low running £ and no fuel
Disadvantages of hydroelectricity
Floods valley + village (small scale)
Rots vegetation = methane & carbon dioxide
Loss of habitat
Initial costs
Wind power advantages
Blades turn generator
No pollution
No fuel and low running costs
No permanent damage to environment
Disadvantages of wind power
Manufacturing pollution
Weather dependant
Extra demand not met
High initial costs
Advantages of solar cells
No pollution
Reliable in a range of climates
Free energy
Needed in remote places
Disadvantages of solar cells
High manufacturing pollution
No supply and demand
High initial costs
Advantages of geothermal energy
Free
Very little damage
Reliable
Generate electricity & heat buildings
Disadvantages of geothermal power
Few suitable locations
High costs for power plant
How to source geothermal energy
In volcanic areas with hot rocks near surface
Slow decay of radioactive elements deep in the earth
Tidal barrages advantages
No pollution
Low running costs
Runs at all times all year as it’s controlled by the gravitational pull of the sun/moon.
Advantages of bio-fuels
Can burnt the same as fossil fuels
Carbon neutral (if same plant at same rate as burning)
Reliable, quick growth, supply all year
Renewable from plant product animal dung
Disadvantages of bio-fuels
Can’t meet increased demand
High cost
Removes forest and burns vegetation so methane and carbon dioxide
Less space for crops
Advantages of fossil fuels
Reliable
Meet any demand
Cost effective - low extraction costs
Energy use decreases with efficiency
Disadvantages of fossil fuels
Coal + oil burning gives of sulfuric acid = acid rain
(Take sulfur our before burn or clean emissions)
Oil spillages, nuclear waste -danger
Risks catastrophe eg fukushima disaster
