d214b121ffcb93def49e2a599d4d39bhjbjbhjbjhbjbb56.pptx
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The document discusses thermal energy and the three methods of heat transfer: conduction, convection, and radiation. Thermal energy is the energy of moving particles and is felt as heat. Heat always moves from warmer objects to cooler ones. Conduction occurs when objects in direct contact transfer heat. Convection involves the transfer of heat through liquids and gases by density differences. Radiation transfers heat through electromagnetic waves like from the sun or a fire.
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d214b121ffcb93def49e2a599d4d39bhjbjbhjbjhbjbb56.pptx
- 1. Heat
- 4. Thermal Energy • Energy is the ability to make things move or change. • All matter (anything with mass that takes up space) is made up of tiny particles that are always moving. • Thermal energy is the energy of the moving particles. This energy is felt as heat. Thermal Energy = Heat
- 5. Heat • Heat ALWAYS moves from a warmer object to a cooler one. This movement is called heat transfer. • As heat moves into an object, it becomes warmer. As heat moves out of an object, it becomes cooler.
- 6. Heat Transfer • When a freshly made cup of coffee is sitting on a counter, it will lose heat because the air around it is cooler than the coffee. • When an ice cube is sitting on a table, the warmth in the air will transfer into the ice cube, melting it.
- 7. Temperature - measure of the average kinetic energy of the particles in a substance - particles in box on right have higher temperature - higher velocity = more KE = higher temperature Both boxes have same temperature - particles have same average velocity/KE - box on right has more thermal energy - energy contained in a substance - more particles
- 8. • Thermal Energy • Thermal Energy: Total of all energies, kinetic plus potential, internal to a substance. • Quantity of Heat:Calorie or Joule • 1 calorie = Amount of thermal energy required to change the temperature of 1 gram of water 1°C. • 1 joule = 0.239 calories (1 Calorie = 4.187 joules) • 1 kilocalorie = 1,000 calories (usually spelled with a capital C)
- 9. Heat Transfer • There are 3 ways that heat can transfer to other objects. These methods of transfer are called conduction, radiation, and convection.
- 10. Conduction • Conduction is the transfer of heat between things that are touching. • When two things that are touching have different temperatures, heat will move from the warmer object to the cooler one. Examples: • Hands are warmed when holding a hot mug of cocoa • A hot stove burner warms a pot sitting on it. • Can you think of some other examples?
- 11. Conductors • Conductors are objects that allow heat to move through them easily. • Metals are good conductors because they allow heat to move through them easily. Examples of metals include iron, silver, copper, aluminum, and stainless steel. • For example, if you were at a campfire and you put a stick in the fire, your hand would not burn. Wood is not a good conductor. If you left a metal spoon in a hot pot on the stove and held the spoon, your hand would burn.
- 12. Convection • Convection is the transfer of thermal energy through liquids or gases. • Warmer air and water rises and cooler air and water sinks. This creates a convection current. Click the picture below for a convection demonstration.
- 13. Radiation • Radiation is the transfer of energy through electromagnetic waves. • Radiation from the sun heats objects on Earth. Heat travels from fire to objects through radiation as well.
- 15. Thermal Energy • Energy is the ability to make things move or change. • All matter (anything with mass that takes up space) is made up of tiny particles that are always moving. • Thermal energy is the energy of the moving particles. This energy is felt as heat. Thermal Energy = Heat
- 16. Heat • Heat ALWAYS moves from a warmer object to a cooler one. This movement is called heat transfer. • As heat moves into an object, it becomes warmer. As heat moves out of an object, it becomes cooler.
- 17. Heat Transfer • When a freshly made cup of coffee is sitting on a counter, it will lose heat because the air around it is cooler than the coffee. • When an ice cube is sitting on a table, the warmth in the air will transfer into the ice cube, melting it.
- 18. Temperature - measure of the average kinetic energy of the particles in a substance - particles in box on right have higher temperature - higher velocity = more KE = higher temperature Both boxes have same temperature - particles have same average velocity/KE - box on right has more thermal energy - energy contained in a substance - more particles
- 19. • Thermal Energy • Thermal Energy: Total of all energies, kinetic plus potential, internal to a substance. • Quantity of Heat:Calorie or Joule • 1 calorie = Amount of thermal energy required to change the temperature of 1 gram of water 1°C. • 1 joule = 0.239 calories (1 Calorie = 4.187 joules) • 1 kilocalorie = 1,000 calories (usually spelled with a capital C)
- 20. Heat Transfer • There are 3 ways that heat can transfer to other objects. These methods of transfer are called conduction, radiation, and convection.
- 21. Conduction • Conduction is the transfer of heat between things that are touching. • When two things that are touching have different temperatures, heat will move from the warmer object to the cooler one. Examples: • Hands are warmed when holding a hot mug of cocoa • A hot stove burner warms a pot sitting on it. • Can you think of some other examples?
- 22. Conductors • Conductors are objects that allow heat to move through them easily. • Metals are good conductors because they allow heat to move through them easily. Examples of metals include iron, silver, copper, aluminum, and stainless steel. • For example, if you were at a campfire and you put a stick in the fire, your hand would not burn. Wood is not a good conductor. If you left a metal spoon in a hot pot on the stove and held the spoon, your hand would burn.
- 23. Convection • Convection is the transfer of thermal energy through liquids or gases. • Warmer air and water rises and cooler air and water sinks. This creates a convection current. Click the picture below for a convection demonstration.
- 24. Radiation • Radiation is the transfer of energy through electromagnetic waves. • Radiation from the sun heats objects on Earth. Heat travels from fire to objects through radiation as well.