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Exploring Thermal Conductivity GOALS Compare heat conductivity of solids Study relation between heat and electrical conductivity.

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Presentation on theme: "Exploring Thermal Conductivity GOALS Compare heat conductivity of solids Study relation between heat and electrical conductivity."— Presentation transcript:

1 Exploring Thermal Conductivity GOALS Compare heat conductivity of solids Study relation between heat and electrical conductivity

2 What is Temperature and Heat? Temperature is a measure of how hot or cold something is. Temperature is the result of the motion of particles which make up the substance (motion: vibrations). Temperature is a measure of how hot or cold something is. Temperature is the result of the motion of particles which make up the substance (motion: vibrations). Heat is the flow or transfer of energy from one object to another one. Heat can flow spontaneously from an object with high temperature to an object with low temperature. Heat is the flow or transfer of energy from one object to another one. Heat can flow spontaneously from an object with high temperature to an object with low temperature. Heat conduction occurs as hot, rapidly moving atoms and molecules interacting with neighboring atoms. Heat conduction occurs as hot, rapidly moving atoms and molecules interacting with neighboring atoms.

3 Heat Conduction Cup full of water does not burn Cup with nothing inside burns Water absorbs heat, which is why the cup did not burn.

4 Heat Conduction w/ Metals Thermometer Temperature Time Lead:.083 Copper:.918 Brass:.260 Aluminum:.504 Copper conducted heat the fastest.

5 Formulas E=1/2 mv 2 = 3/2 kT E: kinetic energy m: mass v: velocity T: temperature E=1/2 mv 2 = 3/2 kT E: kinetic energy m: mass v: velocity T: temperature Resistance of an object, I=V/R I=current, V=voltage in volts, R= resistance in ohms Resistance of an object, I=V/R I=current, V=voltage in volts, R= resistance in ohms Relation between Electrical and Thermal conductivity: k/σ = L*T Relation between Electrical and Thermal conductivity: k/σ = L*T k= thermal conductivity, σ= electrical conductivity, L= “Lorentz” # k= thermal conductivity, σ= electrical conductivity, L= “Lorentz” # Heat flow: Q/t = k * A * (T hot – T cold )/d Q= heat, A= surface, d=distance between the ends, and k= thermal conductivity Conductivity of different metals: Lead= 35.3 wattsAluminium=237 watts Brass= 109 watts Copper= 401 watts

6 Electrical Current/Resistance Electrical current involves electrons moving in the conductor of conductive metals. Current is the flow of free electrons pushed by a difference in voltage. Electrical resistance is a measure of the degree to which an object opposes an electrical current to it. Example for electrical resistance: the longer the conductor, the higher the resistance. The smaller the conductor, the lower the resistance.

7 Comparing Heat and Electrical Conductivity ► Both heat and electrical conductivity have currents that involve electrons moving around freely. ► This was proved by an experiment our group did. We measured electrical conductivity by using copper wire and measuring the electrons moving through it.

8 Conclusion Both electrical and heat conduction were proven to function similarly. Both electrical and heat conduction were proven to function similarly. Copper is the best metal to use to transfer heat. Copper is the best metal to use to transfer heat. This can relate to everyday life because when it comes to cooking, it’s better to use a wooden spoon to stir boiling water. This is because heat cannot travel as fast on wood. Now if a metal spoon, like copper, is used for stirring boiling water, then be expected to get your fingers burned. This can relate to everyday life because when it comes to cooking, it’s better to use a wooden spoon to stir boiling water. This is because heat cannot travel as fast on wood. Now if a metal spoon, like copper, is used for stirring boiling water, then be expected to get your fingers burned.


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