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
