14.7 Thermal Energy - Review
Explain the difference between a renewable and non-renewable resource. A resource that can be replaced in a relatively short period of time Non-Renewable Exist in limited quantities and once used cannot be replaced.
Explain the difference between a renewable and non-renewable resources a.) List the non-renewable resources Oil, natural gas, coal and uranium b.) List renewable resources Solar, wind, hydroelectric, geothermal, biomass
What is solar energy? Energy that turns the heat from the sun into electric energy
What is Geothermal Energy? Energy that turns the heat in the earth into electric energy
What is the Hydroelectric Energy Energy that turns flowing water in kinetic energy and the into electric energy
What is Heat? Transfer of thermal energy from one object to another because of temperature difference.
What is Temperature Measure of how hot or cold an object is compared to a reference.
Heat flows from _____ to _________ Hot Cold
Define the units we use to measure temperature. Celsius
Describe the movement of particles in a sold, a liquid and a gas. Solids Liquids Gas Which state would have the most heat and the highest temperature Slow Medium Fast Gas
Explain how a balloon would behave if you warmed up the air inside of it by a fire. The balloon would expand if placed near a fire What about if you put it in a freezer? The balloon would shrink if placed in a freezer What is the process called? Thermal Expansion
What three things does thermal energy depend on? Mass Temperature Phase (solid, liquid, or gas)
What is specific heat? The amount of heat needed to raise the temperature of 1 gram of a material by 1º C.
What is the equation for heat? Q = m · c ∙ Δt Q = heat (J) m = mass (g) c = specific heat of substance (J/(g·Cº) ΔT = change in temperature (C°)
If the specific heat of iron is If the specific heat of iron is .449 J/gC and a 300 gram piece of iron is heated from 25 - 50 º Celsius then what would be the amount of heat transferred? Q = m · c ∙ Δt Q = 300 g · 0.449 J/(g·Cº) ∙ (50ºC - 25ºC) Q = 3,367.5 J
Define Conduction Transfer of thermal energy by objects touching.
Define Convection Transfer of thermal energy when particles of a fluid move from one place to another.
Define Radiation Transfer of energy by waves moving through space.
Name a good thermal conductor Copper, silver, aluminum, iron, steel, brass, bronze, mercury, dirty water
Name a good thermal insulator Glass, rubber, fiberglass, cotton, paper, wood, plastic, air, pure water
What does the 1st Law of Thermodynamics state? Energy is conserved.
What does the 2nd Law of Thermodynamics state? Thermal energy can flow from colder objects to hotter objects ONLY if work is done on the system.
What does the 3rd Law of Thermodynamics state? Absolute Zero cannot be reached.
What is the value of Absolute Zero? -273.15 ºC -459.67 ºF