2. Starter Directions: Identify as work, kinetic energy, or potential energy. The scenario might apply to more than one. 1.A dog pulling a sled. 2.An apple hanging on an apple tree. 3.A boulder sitting on a cliff. 4.Ski-diver falling from a plane 30,000 ft. 5.A student lifting a stack of wood from the ground to a shelf 10 meters up.

3. Thermal Energy and Heat Day 33

4. Essential Questions When at the beach, explain why the sand is hot yet the water is cold. How are heat and temperature related? How is heat transferred?

5. Teacher Explain: Thermal energy and heat http://studyjams.scholastic.com/studyjams/ jams/science/energy-light-sound/heat.htmhttp://studyjams.scholastic.com/studyjams/ jams/science/energy-light-sound/heat.htm

6. Reading Passage Temperature, Thermal Energy, and Heat As part of your notes answer the analysis questions For some you will need to write the question.

7. Thermodynamics Thermodynamics is the study of heat and conversions between thermal energy and other forms of energy.

8. Kinetic Energy There was more motion in the hot water Matter is always in motion Particles of gases, liquids, and solids all move As the velocity of the molecules increase the more KE which means more thermal energy. The energy of motion is Kinetic Energy

9. Explain: Molecules Kinetic Energy Directions: As a class, discuss and rank according from least to greatest KE of molecules. 1.Bowl of Soup 2.Ice cube 3.Melting Brass 4.Concrete 5.Human Body

10. Work and Heat Work and Heat- work is never 100% efficient. Some is always lost to heat and friction.

11. Heat Heat- the transfer of thermal energy from one object to another because of a temperature difference. In what direction does heat flow spontaneously? –FROM HOT to COLD

12. Temperature Temperature = measure of how hot or cold something is compared to a reference point. Temperature is the average kinetic energy of the particles in an object. In the image below, where is average kinetic energy greater? –Higher temperature

13. http://www.classzone.com/books/ml_science_sh are/vis_sim/mem05_pg101_kintheory/mem05_p g101_kintheory.htmlhttp://www.classzone.com/books/ml_science_sh are/vis_sim/mem05_pg101_kintheory/mem05_p g101_kintheory.html Teacher Explain: Temperature vs. Average Kinetic Energy

14. Heat Heat is related to temperature: The Temperature of an object is the measurement of the average kinetic energy (KE) of particles

15. Explain: Heat Flow Directions: Answer the following questions using the diagram. 1.Which box has more heat? 2.Which box has less heat? 3.The heat flows in which direction and why? The Diagram shows how heat flows from one object to another.

16. Heat Flow Heat flows DOWN the bar through COLLISIONS. Collisions transfer thermal energy from hot to cold.

17. Thermal Energy Thermal energy- total potential and kinetic energy in an object. –It depends on mass, temperature, and phase of an object. Thermal Energy is the overall energy of motion of all particles making up the object. Thermal energy depends on the number of particles in the object. Twice the mass gives twice the thermal (kinetic) energy. Temperature is the “hotness” of the object. Temperature does NOT depend on the number of particles in a body. It depends on the average kinetic energy of the particles. Twice the mass gives the same temperature.

18. Explain: Thermal Energy Directions: As a class, discuss and rank the following items from least to greatest in terms of thermal energy. Boiling Water Melting Iron Ice Cream Electric Iron Water