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Dive into the world of heat and temperature with this comprehensive guide covering topics such as thermal energy, phase transitions, thermodynamics laws, and the importance of understanding pseudoscience. Learn the fundamental concepts of heat flow and energy transfer in various states of matter.
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NS 3310 – Physical Science Studies Chapter 4 – Heat and Temperature
Key Questions • What is heat? What is thermal energy? What is temperature? Is there a difference? • How does heat move around? • Why do some things feel hot and others cold? • How do substances change their state of matter? How is heat involved? • What are the laws of thermodynamics? • What is entropy?
Kinetic Energy of Molecules • Solids • Fluids • Liquids • Gases • Plasmas
Temperature • Temperature measures the kinetic energy of molecules (this is external energy) • Fahrenheit • Celsius • Kelvin (absolute zero)
Thermal Energy • Thermal energy is the internal energy of a molecule • Heat is a measure of the internal energy that has been absorbed or transferred from one body to another • Heat is measured in calories (c) or British Thermal Units (BTUs)
Specific Heat and Latent Heat • Specific heat changes the temperature of an object • Latent heat changes the phase of the material • For example: Ice to Water to Steam
Phase Transitions • Latent Heat of Fusion / Melting • Latent Heat of Vaporization / Condensation • Relative Humidity
Heat Flow • Radiation • Conduction • Convection
Thermodynamics • The First Law of Thermodynamics • Applied Law of Energy Conservation • W = J(QH – QL) • The Second Law of Thermodynamics • Heat always flows from an area of higher concentration to an area of lower concentration • Entropy
Perpetual Motion Machine? • Perpetual Motion Machines • Free Energy • Other Scams
Key Concepts • Thermal energy is the internal and external energy of atoms. • Heat is the transfer of thermal of energy between atoms. • Temperature is a measurement of the kinetic energy of molecules. • Adding heat energy to substances makes their temperature rise (specific heat). • To change the state of a substance requires even more heat (latent heat). • Heat can be transferred by radiation, conduction and convection. • Entropy describes the total energy of a system and tells us that we cannot get more energy out of a system than we put into it.