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Convection and the Mantle. Heat Transfer. Heat always moves from a warmer place to a cooler place. Hot objects in a cooler room will cool to room temperature. Cold objects in a warmer room will heat up to room temperature. Question.
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Heat Transfer • Heat always moves from a warmer place to a cooler place. • Hot objects in a cooler room will cool to room temperature. • Cold objects in a warmer room will heat up to room temperature.
Question • If a cup of coffee and a red popsickle were left on the table in this room what would happen to them? Why? • The cup of coffee will cool until it reaches room temperature. The popsickle will melt and then the liquid will warm to room temperature.
Heat Transfer Methods • Heat transfers in three ways: • Conduction • Convection • Radiation
I. Types of Heat Transfer Three Types: • radiation- transfer of energy through space. Ex: sun warming a metal slide. • Conduction- transfer of energy when materials are TOUCHING. • Ex 1: you’re touching the slide and getting burned. • Ex 2: Pot of hot soup on stove. There is a spoon that has been left in the soup. The eye of the stove touches and heats the pot, the pot touches and heats the soup, the soup and pot touches and heats the spoon. You touch the spoon and the heat is transferred to you.
3. Convection- transfer of heat through movement of currents. a. hot air and water/fluids rise b/c they are less dense. They do not have as many molecules in them and that is why they are lighter and rise. b. cooler air, water and fluids sink b/c they are more dense. They come close and have more molecules in them so they sink.
II. Convection Currents- The heating of a fluid due to currents: Heating, Rising, Cooling, and Sinking. a. Heat from the core and mantle causes convection currents in the mantle. b. These convection currents cause Earth’s magnetic field and the movement of Tectonic plates. The force of push causes plates to move apart( diverging-causes volcanoes). The force of pulling caused plate to move together (converging- causes mtns).
Water movement Cools at the surface Convection current Hot water rises Cooler water sinks
Youtube- warm water rises, cold water sinks • http://www.youtube.com/watch?v=bN7E6FCuMbY • Air rising and sinking • http://www.youtube.com/watch?v=ZPErStqSSMk
Interactive site • http://www.wisc-online.com/Objects/heattransfer/default.aspx
Be the teacher • Explain the difference between radiation, conduction and convection. • With the explanation of what it is, also give examples for each one.
Videos and songs • Mr. Parr Heat transfer song- http://www.youtube.com/watch?v=wr8Z4SCETPs • Bill Nye- Heat • http://www.youtube.com/watch?v=QGyEwNIQUSU
Homework • Complete the Heat Transfer ws.