Particles

Particles

1. Heat Transfer

   • Conduction
     • In Solids Only
     • Occurs when particles are exposed to heat energy, causing them to vibrate and warm up
     • Metals are some of the best conductors because they have a sea of electrons, which are free to move.
       • When it is heated, the electrons gain energy that is then transfred throughout the metal
         • Insulators such as plastics and wood, don;t have this sea of electrons, so they are worse conductors.
   • Convection
     • Heat transfers from Warmer to Cooler areas.
       • So, Cooler (dense) fluids sink through warmer (less dense) fluids.
         • This creates Convection Currents
           • This happens when a Liquid or a Gas is heated, but then cools in a continuous cycle.
     • In Liquids and Gases
   • Radiation
     • Anything Emits or Absorbs Radiation
     • Matt and Black surfaces Absorb and Radiate the Most
     • Shiny and Light surfaces Absorb and Radiate the Least
     • Objects with a large surface area Absorb and Radiate more
   • U Values measure how good an insulator is.
     • The LOWER the value the BETTER insulator it is.
       • U values really show how good it is at transfering heat, that its why a lower value is better when looking at how good an insulator a material is/
   • Evaporation
     • Water takes away energy from your body. This is why puddles dry up on cold days
     • The faster (more energetic) molecules leave first, later followed by the cooler ones.

2. Energy Equations

   • Specific Heat Capacity
     • Usually in J/kg °C
     • The amount of energy (measured in joules) needed to change the temperature of 1kg of the material by 1°C.
   • Energy Transfered
     • m x c x T = E
       • Mass of Object x Specific Heat Capacity x Change in temperature of the object.
     • p x t = E
       • Power x Time
   • Energy Efficency
     • Useful Energy (Output)/Total Energy (Input)
   • Watt Hours
     • Watts x Hours
     • Usually in kWh
     • Electricity bill "Units" are in kWh
       • Simply x by price per unit to get electricity cost

3. Kinetic Theory

   • Matter is anything made out of atoms and molecules.
     • The 3 states of Matter are Solids, Liquids, and Gases
   • As particles heat up, they gain Kinetic Energy
     • This causes the particles to move and spread out, causing a change of state.