S7 Q3 HEAT TRANSFER AND SAVING ENERGY.pptx

S7 Q3 HEAT TRANSFER AND SAVING ENERGY.pptx

1. FUNDAMENTALS OF MOTION

2. HEAT TRANSFER AND SAVING ENERGY When is an object considered hot or cold?

3. Basic concepts of energy and temperature Particles of matter are in constant random motion . INTERNAL ENERGY - The total energy of the particles in a body

4. Basic concepts of energy and temperature TEMPERATURE - measure of the average of motion of particles

5. Basic concepts of energy and temperature The higher the temperature means higher internal energy, if the mass is the same

6. Basic concepts of energy and temperature 1. If two objects have the same mass and temperature, how would you compare their internal energies? 2. What happens to the temperature and internal energy of a substance as you heat it? 3. Which has a greater internal energy: a cup of water at 30 degrees Celsius or a kettle of water at the same temperature?

7. Basic concepts of heat HEAT? - the transfer of internal energy from a warmer object to a cooler one due to the difference in their temperature. HEAT TRANSFER THERMAL EQUILIBRIUM - a condition in which there is no net flow of internal energy

8. Basic concepts of heat 1. What is the difference between internal energy and heat? 2. Under what conditions will heat transfer take place?

9. Chill, relax or be cool

10. MODES OF HEAT TRANSFER CONDUCTION Thermal conductors Thermal insulators

11. MODES OF HEAT TRANSFER CONVECTION

12. MODES OF HEAT TRANSFER RADIATION

13. DIRECTION: Identify the mode of heat transfer involved in each of the following situations. 1. Glider pilots utilize ‘thermals’, upward currents of warm air to ascend to higher altitudes. 2. When you step on a tile heat can transfer more easily from your feet onto the tile.

14. 3. The global movement of the ocean helps distribute heat throughout the Earth. 4. An electric fan makes the air move faster in a room, which can enhance the transfer of warmth from your body into thin air.

15. 5. This mode of heat transfer brings warmth from the Earth's interior to its surface as it pushes the plates under the ground, leading to the occurrence of earthquakes and the formation of volcanoes. 6. Earth also emits heat into space.

16. 7. To prevent ice from melting, use a cooler. 8. When roasting marshmallows, it is better to use a tree twig than a metal rod, as the rod can get very hot and difficult to hold.

17. 9. This method of heat transfer distributes warm air from sunlight throughout the entire house. 10. The sun provides warmth to a person standing under its light.

18. 1. Convection 2. Conduction 3. Convection 4. Convection 5. Convection 6. Radiation 7. Conduction 8.Conduction 9. Convection 10. Radiation

19. FELIX MARAMBA

20. SAVING ENERGY PASSIVE COOLING

21. TECHNOLOGIES IN TRANSFORMING HEAT INTO ELECTRICAL ENERGY 1. THERMOMAGNETIC GENERATORS

22. TECHNOLOGIES IN TRANSFORMING HEAT INTO ELECTRICAL ENERGY 2. THERMAL PHOTOVOLTAIC CELLS