Chapter 5-6 Energy and Thermal Energy Review

Study Strategies and Resources

• Digital textbook access is available through the Hebron Launchpad via the McGraw Hill tile.

• Recommended vocabulary study methods:

  • Flashcards (paper or digital).

  • Folded sheet method: Fold a single sheet of lined paper vertically in half, writing vocabulary terms on the left side and definitions on the right side.

  • Vocabulary definitions can be found in class notes or the textbook glossary.

• Recommended concept review methods:

  • Review class notes and quizzes.

  • Complete test review activities located at the end of each chapter in the digital textbook.

Key Vocabulary Terms

• Radiation: The transfer of energy by electromagnetic waves.

• Thermal Energy: The sum of kinetic energy and potential energy of the particles that make up a material.

• Conduction: The transfer of thermal energy between materials by the collisions of particles.

• Thermal: Relating to heat or thermal energy.

• Conductor: A material through which thermal energy flows easily.

• Thermal Insulator: A material through which thermal energy does not flow easily.

• Specific Heat: The amount of thermal energy required to increase the temperature of $1\,\text{kg}$ of a material by $1\,^\circ\text{C}$.

• Thermal Expansion: An increase in a material's volume when its temperature increases.

• Thermal Contraction: A decrease in a material's volume when its temperature decreases.

• Convection: The transfer of thermal energy by the movement of particles from one part of a material to another.

• Convection Current: The movement of a fluid caused by differences in temperature and density.

• Energy: The ability to cause change.

• Kinetic Energy: Energy due to motion.

• Potential Energy: Stored energy due to the interactions between objects or particles.

• Work: The transfer of energy that occurs when a force is applied over a distance.

• Mechanical Energy: The sum of potential energy and kinetic energy in a system of objects.

• Sound Energy: Energy carried by sound waves.

• Electric Energy: Energy carried by an electric current.

• Radiant Energy: Energy carried by electromagnetic waves.

• Nuclear Energy: Energy stored and released from the nucleus of an atom.

• Chemical Energy: Energy stored in the chemical bonds between atoms.

• Law of Conservation of Energy: Energy can be transformed from one form to another or transferred from one region to another, but energy cannot be created or destroyed.

Energy Classification and Climate Impact

• Renewable Energy: Energy resource that is replaced as fast as, or faster than, it is used.

• Nonrenewable Energy: Energy resource that is available in limited amounts or that is used faster than it is replaced in nature.

• Environmental Impact of Greenhouse Gas Emissions:

  • Carbon dioxide ($\text{CO}_2$) and methane ($\text{CH}_4$) impact the environment by causing global warming.

• Historical Climate Benchmark:

  • The year 1880 is significant to scientists as it marks the beginning of reliable global temperature record-keeping and climate tracking.

Thermal Energy Transfer and Properties

• Three Modes of Thermal Energy Transfer:

  • Conduction: Heat transfer through direct physical contact and collision of particles.

  • Convection: Heat transfer through fluid movement caused by density and temperature differences.

  • Radiation: Thermal energy transfer through electromagnetic waves without requiring a physical medium.

• Specific Heat Dynamics:

  • The higher the specific heat of an object, the more thermal energy required to change that object's temperature.

Energy Transformations in Power Systems

• System Energy Transformations:

  • In any given system, energy changes continuously from one form to another while conserving the total amount of energy.

• Step-by-Step Energy Flow in a Nuclear Power Plant:

  1. Radioactive nuclei are broken apart, changing nuclear energy into thermal energy.

  2. Thermal energy heats water to produce steam.

  3. Steam spins a turbine, changing thermal energy into mechanical energy.

  4. The spinning turbine operates a generator, changing mechanical energy into electrical energy.

Temperature Scale Conversions

• Converting Fahrenheit to Celsius:

  • Equation:     ${^\circ\text{C}} = \frac{({^\circ\text{F}} - 32)}{1.8}$

  • Conversion Steps:

  1. Always perform the operation in parentheses first (${^\circ\text{F}} - 32$).

  2. Divide the result from Step 1 by $1.8$

  • Worked Example (Converting $176^\circ\text{F}$ to Celsius):

  1. Perform parentheses operation:        $176 - 32 = 144$

  2. Divide by $1.8$:        $\frac{144}{1.8} = 80^\circ\text{C}$

  3. Final converted value: $80^\circ\text{C}$

• Converting Celsius to Fahrenheit:

  • Equation:     ${^\circ\text{F}} = ({^\circ\text{C}} \times 1.8) + 32$

  • Conversion Steps:

  1. Multiply the temperature in Celsius by $1.8$

  2. Add $32$ to the resulting product.