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Thermal Heat and Energy. Chapter 8. Temperature, Thermal Energy, and Heat. Lesson 1. Big ?’s. What Determines the Temperature of an Object? What is Thermal Energy?. What Determine the Temperature of an Object?. Temperature is a measure of how hot or cold something is.
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Thermal Heat and Energy Chapter 8
Big ?’s • What Determines the Temperature of an Object? • What is Thermal Energy?
What Determine the Temperature of an Object? • Temperature is a measure of how hot or cold something is. • Technically Temperature is a measure of the average kinetic energy of the particles in an object. • Measurements: • Fahrenheit Scale (℉) • United States • Celsius Scale (℃) • Everyone else • Kelvin Scale (K) • Absolute Zero is the lowest temperature possible (-273℃)
What Is Thermal Energy? • Thermal Energy is the total energy of all the particles in an object. • Depends on (1) temperature, (2) number of particles, and (3)particle arrangement. • More particles = More thermal energy • Heat is the transfer of thermal energy from a warmer object to a cooler object.
The Transfer of Heat Lesson 2
Big ?s • How is Heat Transferred?
How Is Heat Transferred? • Heat is transferred from warmer areas to cooler areas by (1) conduction, (2) convection, and (3) radiation. • Only in one direction
Types of Heat Transfer Conduction • Heat transfer between particles of matter. • Direct contact. Convection Radiation Heat transfer through electromagnetic waves. Matter not required • Heat transfer in fluids (liquids & gases). • Convection Current: warm fluids rise, cools down, and falls back down.
Thermal Properties Lesson 3
How Do Different Materials Respond to Heat? Conduct: allows something to travel through it • Conductors • Materials that conduct heat well. • Ex: copper, aluminum, gold, and silver • Insulators • Materials that do not conduct heat well. • Ex: glass, air, plastic, rubber, and wood
Specific Heat • Different materials heat up at different rates. • Specific Heat: the amount of energy required to raise the temperature of 1 kilogram of a material by 1 kelvin (K) • Measured in joules per kilogram-kelvin (J/(kg-K) Energy Change = Mass X Specific Heat X Temperature Change
Thermal Expansion • Thermal Expansion: when the thermal energy of matter increases, its particles usually spread out, causing the substance to expand. • Exception: Water; water expands when it freezes.