1. - Review transfer of heat by conduction and convection; class activity on “warmth” of objects - Study the effects of thermal conductivity on temperature - Quantify the amount of thermal energy required to raise the temperature of water TODAY’S OUTCOMES: HEAT

2. A fan blowing on a thermometer does not change its reading. However, you feel colder when the wind blows because you are not in thermal equilibrium with your environment. Wind blowing transfers thermal energy from your body to the air around you by convection. >The wind certainly makes you feel cold. Does a fan blowing on a thermometer change its reading? (See for yourself! It has been set up at the front of the room.) Even though both thermometers and people have red noses, they differ in the effect that the wind has on them. Discuss the other respects in which you differ from a thermometer that that might explain this. >Why does metal generally feel cold to the touch? (Do humans make very good thermometers?) Metal feels “cold” because it is a conductor of heat - it conducts heat away from your body, whereas an insulator “holds” the heat in the region you are in contact with. Humans make poor thermometers because we are always transferring heat to our environment (in this case, by conduction).

3. >A hot-air balloon uses a gas burner to heat up the air beneath an inflated open balloon. Explain how this is related to an activity you did. What happens to the potential energy of the hot-air balloon as it rises? Convection of air causes warm air to rise, just as the colored water rose in the container when it was warmer than the water around it. When the balloon rises, its potential energy increases; this energy came from the thermal energy in the hot air (overall energy is conserved). Whole Class Activity: Is fur warm? Is glass cool? Furry mittens or woolly socks make you warm. What effect do they have on a thermometer? Last class we wrapped up some thermometers in various ways. Now we will see what temperatures they read. One thermometer was wrapped up in a sock. One thermometer was sealed in a bag with some water. One thermometer was wrapped with aluminum foil. One thermometer was covered with sand in a glass jar. One thermometer was left unwrapped, lying on a paper towel. What effect did wrapping the thermometers have?

4. How thermal energy (heat) moves: - Thermal energy tends to flow from regions of higher temperature to regions of lower temperature - Conduction: thermal energy moving through a substance, without any of the substance moving (slow; the only way heat can move through solids) - Convection: thermal energy moving by way of motion of the substance itself, carrying the heat with it (faster; this only works in liquids & gases) Are there any other ways heat can move? We will see later on......

5. - Thermal energy can move by conduction or convection - conduction is the slowest way heat can move; convection is faster but only works in fluids - Some objects and substances feel “cold” because they transfer thermal energy away from your body, not because they are a lower temperature WHAT YOU ARE EXPECTED TO KNOW:

6. - Review transfer of heat by conduction and convection; class activity on “warmth” of objects ✓ - Study the effects of thermal conductivity on temperature - Quantify the amount of thermal energy required to raise the temperature of water TODAY’S OUTCOMES: HEAT