1. Heat Transfer
Investigation 4 Part 1

2. Solar Energy and Heating
If each Earth material received the same amount of solar energy, how can you explain the differences in temperature?
Water takes five times more heat energy to raise an amount of water one degree than it takes to raise the temperature of an equal amount of dry soil or sand one degree.
Solid earth materials heat faster than water.
In our demonstration, both materials absorbed the same amount of energy, but the water didn’t get as hot.

3. RADIATION Energy comes from the sun as radiant energy.
Radiant energy travels as waves through space and air.
Radiation from the Sun can be visible (light), or invisible like infrared radiation, ultraviolet radiation, X-ray, radio, and other wavelengths.

4. RADIATION, cont.
***When radiant energy strikes an atom or molecule, like a water molecule or a molecule in sand, soil, or air, the molecule gains energy and begins to move faster or vibrate more.
We say that the molecule absorbed the radiant energy.
Absorbing radiant energy is one way energy transfers to matter.
Molecular motion is heat: The more motion in the molecules of matter, the hotter it is.

5. RADIATION, cont.
Radiation is one way energy can travel over great distances or short distances.
When you stand in the sunshine, you are receiving energy from 150 million kilometers away.
When you reach out to warm your hands at a campfire, radiant energy given off by the blaze a meter or two away is absorbed by molecules in your skin, and your hands warm up.

6. Differential Heating
Different materials heat up at different rates, this is called differential heating.
Differential heating accounts for the difference in the temperature of water and soil after they have both been in the sunshine for the same length of time.
Water in oceans and lakes can store more heat than can landmasses even though the temperature of the water may be lower.