1. Heat Transfer Investigation 4

2. What are Earth Materials? Sand Air; different layers of the atmosphere (troposphere, mesosphere, etc) Dirt, soil Water; lakes, rivers, oceans

3. Consider this question:. If each earth material received the same amount of solar energy, how can you explain the differences in temperature? DISCUSS THIS WITH YOUR TABLE GROUPS! You have 2 minutes. GO!

4. Water It takes 5 times more heat energy to raise an amount of water 1 o than it takes to raise the temperature of an equal amount of dry soil or sand one degree. When the same amount of heat energy is absorbed equally by all materials, the temperature of sand and dirt will go up faster than water. Look at illustration on white board

5. Radiation Energy from the Sun is radiant energy. Radiant Energy travels as waves through space and air. Radiation from the Sun can be visible light or invisible like infrared, ultraviolet, microwave, X-ray, radio waves.

6. Light Spectrum This is all the wavelengths of light which reach Earth from the Sun.

7. How Radiation Works When radiant energy hits an atom or molecule, that molecule gains energy and begins to move faster. Let’s look at the FOSS multimedia to see radiation of water in pot. Then you will draw it and explain it.

8. Heat Defined Heat is really movement of atoms and molecules. Energy of motion is called Kinetic Energy Solids: the atoms vibrate back and forth Liquids and Gases: the atoms move a lot! Soooooooo, the more motion atoms have the more kinetic energy they have and so the more heat they have.

9. How does heat transfer from one place to another? Heat can transfer- this is called heat flow. Heat always flows from hotter locations to cooler locations, never the other way around. Cold is simply the absence of kinetic energy Heat is absorbed by a molecule when it starts to move faster. See the yellow diagram on pg. 23 of your textbook

10. Conduction Defined When energy transfers from one place to another by contact. Examples: hot pizza and your mouth, hot cocoa and the cup and then your hand--  A CUP OF HOT

11. 3 Ways to transfer heat: Radiation- energy that travels in WAVES. Examples include: warming hands by a fireplace, sunlight warming your face Conduction- energy that transfers by contact. Examples include: touching a warm cup of cocoa with your hands, burning your mouth with a hot slice of pizza. Reradiation: Earth materials such as the sand or the ocean give off infrared radiation to the atmosphere

12. Heat Transfer to the Atmosphere Air is 99% nitrogen and oxygen molecules, but these do not absorb visible or infrared radiation. Only WATER VAPOR AND CARBON DIOXIDE ABSORB radiant energy mostly infrared rays. Land and oceans absorb visible light. Air molecules that are in contact with the warm land and warm molecules gain energy by conduction.

13. Reradiation Earth actually gives off infrared radiation which is absorbed by water molecules and CO 2 molecules in the atmosphere. Soooooo most of the atmosphere is not heated from above, but really from the Earth reradiating (bouncing back up) from the Earth.

14. Themperature and Thermometers Temperature is a measure of the average kinetic energy of molecules in a material (say water or the air). Let’s use your textbook to review how a thermometer works pg 25

15. Differential Heating Different materials heat up at different rates. Accounts for the difference in the temperature of water and soil after they have both been in the sun for the same amount of time. Water in oceans and lakes can store more heat than landmasses, mainly because they are bigger and have more atoms.