Heat and Temperature
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Heat and Temperature. Temperature. The measure of the average kinetic energy of all of the particles within an object. . Temperature and Energy. All particles are moving and have kinetic energy. We can not measure the KE of each molecule, so we take an average of each one.
Heat and Temperature
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Presentation Transcript
Temperature • The measure of the average kinetic energy of all of the particles within an object.
Temperature and Energy • All particles are moving and have kinetic energy. • We can not measure the KE of each molecule, so we take an average of each one. • Taking temperature is finding the average KE of molecules. • Feeling hot or cold is a rough estimate. • It is subjective.
Thermometer • A device that measures temperature • Most thermometers rely on the expansion of either fluids or metal (mercury) to work. • Electric thermometers rely on a change in current.
Celsius-Fahrenheit Celsius – Fahrenheit Conversion Equation Fahrenheit temperature = (9/5 X Celsius temperature) + 32.0 TF = 9/5t + 32.0
Fahrenheit-Celsius Fahrenheit – Celsius Conversion Equation Celsius temperature = 5/9 (Fahrenheit temperature – 32.0) T = 5/9(TF– 32.0)
Kelvin • Based on Absolute Zero (theoretical) • The temperature at which an object’s energy is minimal Celsius – Kelvin Conversion Equation Kelvin temperature = Celsius temperature + 273 T = t + 273
Relating Temperature to Energy Transfer as Heat You feel hot and cold because of transfer of energy. Molecules must come into contact with one another. Hot = absorbing energy from object Cold = releasing energy from object
Heat The transfer of energy from the particles of one object to those of another object due to a temperature difference between the two objects
Thermal Energy Equation Q = m ΔT C Q = change in thermal energy (J) m = mass (kg) ΔT = change in temperature (˚C) C = specific heat (J/kg ˚C)
Problem Plug and Chug Q = 0.5 kg • 60 ˚C• 800 J/kg ˚C mass x change of temp x specific heat Q = 24,000 J