Chapter 7 Heating and Cooling

How living things adapt … AnimalAdaptation Humans keep warm by Some birds keep warm by Snakes and lizards keep warm by Dogs cool off by Honey bees cool their hives by People cool off by

HVAC Heating Ventilation Air conditioning Cooling Excellent jobs; apprenticeship opportunities TRADES-HRAC-HEATING-REFRIGERATION-AIR- CONDITIONING/_/N-lpqj

If we are serious about reducing the energy consumption of our homes to save money and reduce our use of valuable resources –what can we do to cool our homes in summer and warm them in winter? Wood fireplaces Draft blockers at base of doors and windows Blinds on windows Shade trees around house Create breeze corridors

The Particle Theory of Matter (again!)  All matter is made up of tiny particles.  Particles have spaces between them.  Particles are moving all the time.  Particles move when they are heated.  Particles attract each other.

Heat, Temperature and Thermal Energy Heat is the transfer of energy from warmer things to cooler things. How does this happen? (best answer please) A.particles have self-regulated thermometers B.collisions between particles C.thermal energy jumps form particle to particle D.only special particles carry heat

Since particle are always moving we say that they have …. A.thermal energy B.potential energy C.electric energy D.kinetic energy Temperature is defined as the measure of average _______ of particles. A.thermal energy B.potential energy C.electric energy D.kinetic energy

The higher the temperature … A.the less the average kinetic energy of the particles. B.the greater the average kinetic energy of the particles. Thermal energy is defined as the total kinetic energy of the particles and the energy of attraction between them. Recal that I gave you a bag full of corks representing thermal energy. You then had to share them among the “particles” in your group. The average corks per person represented temperature and the total number of corks represented thermal energy.

Use the particle theory to explain thermal expansion and contraction. Volume increases If volume cannot increase pressure increasesDensity decreases: particles per unit volume Moving particles have more collisions More collisions cause forces of attraction to weaken Particles move farther apart from each other Add thermal energy Thermal energy is converted to kinetic energy of particles Particles move more

Use the particle theory to explain thermal expansion and contraction. Volume decreases Contraction/ less pressureDensity increases: particles per unit volume Moving particles have fewer collisions Fewer collisions cause forces of attraction to strengthen Particles move closer together. Remove thermal energy Kinetic energy is converted to thermal energy of particles Particles move less