1. Heat and Heat Transfer

2. EQ: How can Thermal Energy (heat) be transferred from one object to another?

3. Forms of Energy Mechanical Electrical Electromagnetic Nuclear Chemical
Sound
Thermal

4. HEAT (Thermal Energy)
Created by the movement of particles (atoms) that produces heat.
Energy can take on many forms and can change from one form to another.
Many different types of energy can be converted into heat energy. Light, electrical, mechanical, chemical, nuclear, sound and thermal energy itself can each cause a substance to heat up by increasing the speed of its molecules.
put energy into a system and it heats up, take energy away and it cools.

5. Heat (Thermal Energy)
The more energy that goes into a system, the more active its molecules are. The faster molecules move, the more heat or thermal energy they create. The amount of heat a substance has is determined by how fast its molecules are moving, which in turn depends on how much energy is put into it.

6. Heat
Heat (thermal energy) is transferred from one object to another when the objects are at different temperatures.
Thermal Energy always moves from a warmer object to a cooler object

7. Thermal Energy moves through matter in 3 ways: Conduction Convection
How does heat move?
Thermal Energy moves through matter in 3 ways:
Conduction
Convection
Radiation

8. Conduction The transfer of heat by direct contact (particles collide)
“the process that moves energy from one object to another when they are touching physically”
The transfer of heat by direct contact (particles collide)
Physical contact must be made for conduction to occur

9. Conduction Occurs most easily in solids and liquids
In order for conduction to occur, objects must be at different temperatures and must come into contact with each other
Occurs most easily in solids and liquids

10. Conductors
Conductor - “substances that transfer thermal energy very well”
Conductors have a low specific heat in most cases
Example: copper, gold, and iron

11. Insulators Insulator- “substances that do not transfer heat very well”
Electrons move extremely slow through good insulators
Electrons are tightly bound to the atoms in good insulators and electrons are not free to move around
Good Insulators: wood, plastic, foam, rubber, glass

12. Convection “ the flow of currents in a liquid or gas”
The process that transfers energy by the movement of large numbers of particles in the same direction within a liquid or gas.
Kinetic energy increases, particles spread out over a large area.
“ the flow of currents in a liquid or gas”
A current is created when the warmer (less dense) material rises forcing the cooler (more dense) material to sink

13. How does convection happen??
Kinetic energy increases -> particles spread out
Increased distance between particles -> decrease in the density
Cooler, denser mass of the gas of liquid replaces a warmer, less dense mass of the gas or liquid by pushing it up
Convection is a cycle in nature responsible for most winds and ocean currents.

14. How does convection happen??

15. How does convection happen??

16. How does convection happen??

17. Convection Hot air rises in the atmosphere as cool air sinks
EXAMPLES OF CONVECTION:
Hot air rises in the atmosphere as cool air sinks
Hot water rises to the top (rolling boil) as cold moves to the bottom of the pot to be heated up and sent to the top of the water again.
In a fire, you are always told to get on all fours and crawl across the floor because the warm air (smoke filled) will rise and cool air (non-smoke air) will sink to the bottom.
A basement in a house is known for being naturally cooler than an attic (which is known for being hot/warm) because of convection.

18. Radiation
“Heat transfer through space by electromagnetic waves (light)”
Visible light
Microwaves
Infrared light
The Sun is the most significant source of radiation on Earth
ALL OBJECTS emit SOME radiation
ALL OBJECTS absorb radiation
Can travel through empty space, occurs in solids, liquids, and gasses.
Moves from warmer to cooler objects

19. Examples of Radiation
Waves such as visible light, infrared, and ultraviolet light
Heat from a light bulb
Microwave oven
You get a sunburn from being in the sun too long
Cooking a hamburger over a charcoal flame

20. Radiation

21. Radiation