How is energy transferred?
Opening Assignment What is the primary energy source that drives all weather events, including precipitation, hurricanes, and tornados? A. the Sun B. the Moon C. Earth’s gravity D. Earth’s rotation
How is heat transferred? Conduction! Convection! Radiation!
What is conduction? Heat is transferred from one particle of matter to another without the movement of the matter. Hot atoms and molecules come in contact with cool atoms and molecules and heat is transferred!
http://tdflashzone.net23.net/index.php?p=2_73 Slide 5
When do you experience heat transfer by conduction When you walk on a hot sidewalk or hot sand on the beach, the sand warms—or burns—your feet through conduction. When a warmer substance with quickly moving molecules (the sand) comes into contact with a cooler substance with slowly moving molecules (your bare feet), the faster molecules bump into the slower ones and make them move faster, too.
Youtube video Eureka! Episode conduction
What is convection? Convection is heat transferred by movement of currents in a liquid or a gas (like air). Hot fluids (air or liquids) rise! Cold fluids sink!
Why do hot fluids rise? Why do cool fluids sink Density!!! Heat caused the molecules to move faster and expand. They become less dense. The colder, more dense fluid sinks
Youtube video Convection Currents TeacherAJH Convection Currents - YouTube
Convection in the mantle
Heat transfer from the center of Earth to the surface
Examples in real life Why is upstairs in your house always hotter than your basement?
Radiation! Radiation is the transfer of energy by electromagnetic waves. Sun Heat from a fire lamp Radiation does not require matter to transfer heat
The diagram below represents an experiment on different types of soil. The thermometers are measuring the temperature of the center of the soil samples. The temperatures are different. Why
A. conduction within different soil types The thermometers are measuring the temperature of the center of the soil samples. Which of the following is a cause of the measured difference in the temperature of the two soils? A. conduction within different soil types B. condensation within different soil types C. radiation emitted by different soil types D. convection in the air above different soil types
MCAS Question Heat from deep in Earth's interior is transferred to its crust by which of the following? A. conduction in the ocean B. convection in the mantle C. radiation from the solid core D. evaporation at mid-ocean ridges
Opening Assignment You want to pour very hot coffee into a cup so you can drink it after it cools down…. Which cup is a better choice? Why?
Conductors and Insulators A conductor transfers thermal energy or heat well. An insulator does not! Metals such as silver and stainless steel are good conductors.
Insulators A substance/material that heat or electrical current cannot flow though well
Insulating window
Other insulators List some other materials you know that are good insulators.
Heat absorption On a very hot day in the summer what color shirt should you wear?
Answer Black or dark colors absorb radiation from the sun. White or shiny objects reflect the sun’s radiation
Conductors a conductor is a material conducts heat well and electrical charges can easily flow through.
The end.