THERMAL ENERGY AND HEAT Jennefer Cardenas. Objectives Students will be able to identify and know...
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Transcript of THERMAL ENERGY AND HEAT Jennefer Cardenas. Objectives Students will be able to identify and know...
THERMAL ENERGY AND HEAT
Jennefer Cardenas
Objectives
Students will be able to identify and know difference between THERMAL ENERGY, TEMPERATURE, and HEAT.
Students will be able to identify the 3 ways heat is transferred.
Students will be able to compare different conductors and insulators.
Students will be able to compare Celsius and Fahrenheit Scale.
TEMPERATURE
The measure of the average kinetic energy of the individual particles in an object.
Matter is made up of tiny particles called atoms and molecules. These particles are always in motion even if the object they make up isn’t moving at all. Energy of motion is called kinetic energy, so all particles of matter have kinetic energy. The faster the particles are moving, the more kinetic energy they have.
WATER AND DYE EXPERIMENT
Why did the dye in hot water move faster than the dye in cold water?
The results have to do with the different temperatures of the water.
Back to Experiment
So what explanation would be given if we heated the cold water. Its particles will start moving faster, so their
kinetic energy will increase. This means that the temperature of the water will rise.
THERMAL ENERGY
The total energy of all the particles. If 2 samples of matter are at the same
temperature they do not necessarily have the same total energy.
What is Heat?How is heat transferred?
Heat is thermal energy moving from a warmer object to a cooler object.
There are 3 ways that heat can move. Conduction Convection Radiation
CONDUCTION
Heat conduction or thermal conduction is the transfer of thermal energy through matter, from a region of higher temperature to a region of lower temperature, and acts to equalize temperature differences.
It is also described as heat energy transferred from one material to another by direct contact.
CONVECTION
Convection is the movement of molecules within fluids ( a liquid or a gas); the warm fluid rises and cooler fluids flow in to replace it. This creates a circular flow.
More Convection
The wind we feel outside is often the result of convection currents. You can understand this by the winds you feel near an ocean. Warm air is lighter than cold air and so it rises. During the daytime, cool air over water moves to replace the air rising up as the land warms the air over it. During the nighttime, the directions change -- the surface of the water is sometimes warmer and the land is cooler.
RADIATION
The transfer of energy by electromagnetic waves.
Radiation does not require matter to transfer thermal energy.
Radiation
The sun's rays travel in straight lines called heat rays. When it moves that way, it is called radiation.
When sunlight hits the earth, its radiation is absorbed or reflected.
Conductors and insulators
A conductor is an object that can conduct heat well
An insulator is an object that conducts heat poorly.
ASSESMENT
What are the 3 ways heat is transferred Convection, Conduction, and Radiation TRUE or FALSE The transfer of energy by electromagnetic waves is
the definition for Convection False
TRUE or FALSE In this picture “B” is representing a heat conductor and “A” is representing heat convection?
True