1. Thermal Energy Chapter 6

2. Describe things you do to make yourself feel warmer or cooler.

3. Matter in motion The matter around you is made of tiny particles- atoms and molecules These particles are in constant motion Because they are moving they have kinetice energy The faster they move the more kinetic energy they have These particles move faster in hot objects then cooler objects.

5. Temperature and Heat Temperature- related to the average kinetic energy of an objects atom’s or molecules. Thermal Energy- the sum of the kinetic and potential energy of all the atoms in an object. -thermal energy increases as temperature increases. -At constant temperature, thermal energy increases if mass increases Thermal energy that flows from something at a higher temperature to something at a lower temperature is called HEAT.

6. Specific Heat- amount of heat needed to raise the temperature of 1kg of a material by 1 degree C or K. Changes in thermal energy can be calculated as change in thermal energy equals mass times change in temperature times specific heat. 1.When heat flows into an object and its temperature rises, the change in temperature is positive. 2. When heat flows out of an object and its temperature decreases, the change in temperature is negative. 3. A calorimeter is used to measure specific heat.

7. Actions that increase thermal energy Raise the temperature of an object Pull atoms or molecules that attract one another farther apart Add mass to the object, without changing its temperature Explanation Increases the kinetic energy of the atoms or molecules Increases the potential energy of the atoms or molecules More molecules at the same level of energy means more total energy in the object

8. Specific heat

9. Water as a coolant Water has the highest specific heat Water can absorb heat without a large change in temperature. For example: Water is used as a coolant in an automobile.

10. Measuring specific heat Can be measured through the use of a calorimeter. The mass of the sample is measured, as is the initial temperature of the water in the calorimeter. The material is then heated, temperature measured, and the sample is placed in the inner chamber.

11. How do temperature and heat differ?

12. Transferring Thermal Energy Conduction - transfer of thermal energy through matter by direct contact of particles -Kinetic energy is transferred as particles collide -Solids, particularly metals, are good heat conductors

13. The best conductors of heat are metals. Silver and aluminum and copper are the best conductors of heat

14. Convection- the transfer of energy by the motion of heated particles in a fluid. Convection currents transfer heat from warmer to cooler parts of a fluid. Convection currents create rain forests and deserts over different regions of Earth.

15. Radiation- energy transfer by electromagnetic waves Some radiation is absorbed and some is reflected when it strikes a material. Heat transfer by radiation is faster in a gas than in a liquid or solid

17. Compare and contrast radiation, convection, and conduction.

18. How can you control heat flow? Humans use clothing, jackets..etc… Animals have blubber, thick coats, scaly skin, feathers, color of skin, etc…. What are some items you use to control heat flow?

19. Insulator- material that does not let heat flow through it easily Gases such as air usually make better insulators than liquids or solids A vacuum layer in a thermos is a good insulator because it contains almost no matter to allow conduction or convection to occur.

20. Most living things control the flow of heat by using special features such as fur,feathers, blubber, or scales

21. What types of heating systems are used in your home?

22. USING HEAT Heating Systems-Warm homes and buildings 1.Forced air system- fuel haets air, which is blown through ducts and vents; cool air is returned to the furnace to be reheated. 2.Radiator System- hot water or steam in a radiator transfers thermal energy to the air 3.Electric Heating System- electrically heated coils in ceilings or floors heat air by conduction

23. Solar Energy- energy from the sun Passive solar heating does not use mechanical devices to move heat. (windows in a home) -Active solar heating use solar collectors to absorb radiant energy, which is circulated through the building

24. THERMODYNAMICS Thermal energy, heat, and work are related and the study of their relationship among them. Heat and work increase thermal energy The first law of thermodynamics- the increase in thermal energy of a system equals the work done on the system plus heat transferred to the system. Closed system- no energy is added to a system Open system- energy is added to a system The second law of thermodynamics- heat cannot flow from a cool object to a warmer object unless work is done

25. Heat Engine- an engine that converts thermal energy into mechanical energy Internal Combustion Engine- Burns fuel inside the engine in chambers or cylinders. Internal combustion engines convert only 26% of the fuel’s chemical energy to mechanical energy.

26. Heat Mover - a device that removes thermal energy from one location and transfers it to another location at a different temperature. Refrigerator- contains a coolant that absorbs heat from the inside of the refrigerator and releases it on the outside as heat. Air conditioner- Cools warm air Heat pump- can both cool and warm air The human body stays cool by EVAPORATION of sweat.