Physics 1A - Energy

Physics 1A - Energy

1. Heat Radiation

   • Convection
     • Involves Particles
     • Mainly Liquids and Gasses
     • Hotter Particles lose Density and start to rise, taking their heat energy with them
   • Conduction
     • Involves Particles
     • Mainly Solids
     • Collisions of particles
   • Radiation
     • Uses InfraRed Radiation
     • Can be emitted by solids, liquids or gasses
     • Emission of EM waves
     • Matt Black = Absorb
     • Shiny White = Reflect

2. Condensation + Evaporation

   • Condensation = Gas →Liquid
     • Evaporation's the opposite
   • Factors increasing Rate of Evaporation
     • High Temp
     • Low Density
     • Large Surface Area
     • More Airflow over liquid
   • Factors increasing Rate of Condensation
     • Low Temp (of Gas)
     • Low Temp (of Surface)
     • High Density
     • Less Airflow

3. Specific Heat Capacity

   • How much energy stuff can store
   • E = M x C x θ
   • Energy Transferred (J) = Mass (kg) x SHC (j/kg) x Temp Change (°C)

4. Energy Transfer

   • Electric
   • Light
   • Sound
   • Kinetic
   • Nuclear
   • Thermal
   • Gravitational Potential
   • Elastic Potential
   • Chemical
   • GP, EP & Chemical Energy are stored energy waiting to be transferred into another type
   • Energy can't be created or destroyed

5. Efficiency

   • Efficiency = Useful Power Out ÷ Total Power In
     • For Energy, Just replace 'Power' with energy
   • Efficiency can be given as a decimal or percentage

6. Cost of Energy

   • Energy = Power x Time
     • Units = kW x Hours
       • Units = kWh
   • Cost = Energy x Price p/ Unit
   • Energy = No. of Units