Physics: Conservation of Energy

Energy Types

• Energy is neither created nor destroyed, only converted from one type to another
• Types of energy:
  • Gravitational potential energy (GPE)
  • Kinetic energy (KE)
  • Thermal energy
  • Radiant energy
  • Chemical energy
  • Electrical energy
  • Nuclear energy

Gravitational Potential Energy (GPE)

• GPE is based on an object's height
• Calculated using the equation: GPE = mgh (mass, acceleration due to gravity, and height)
• Higher objects have more GPE

Kinetic Energy (KE)

• KE is greater if an object moves faster
• Calculated using the equation: KE = 1/2 mv^2 (mass and velocity)

Thermal Energy

• Thermal energy is due to the movement of particles in an object
• Higher thermal energy when particles are moving quickly, lower thermal energy when particles are moving slowly
• Can be transferred through:
  • Convection
  • Conduction
  • Radiation

Radiant Energy

• Radiant energy can transfer through empty space (vacuum)
• Types of radiant energy:
  • Electromagnetic radiation
  • Gravitational radiation
• Both types of radiant energy do not require matter to propagate
• Electromagnetic radiation can take the form of oscillating waves or particles called photons
• Gravitational radiation takes the form of waves that propagate through the curvature of spacetime
• All radiant energy travels at the speed of light (~300,000,000 meters per second)

Chemical Energy

• Chemical energy is stored in the bonds of chemical compounds
• A form of potential energy
• Exothermic reactions release energy, endothermic reactions absorb energy
• Examples of chemical energy:
  • Photosynthesis
  • Petroleum
  • Batteries

Electrical Energy

• Electrical energy is caused by moving electric charges
• Energy is the ability to do work or apply force to move an object
• The faster the electric charges move, the more electrical energy they carry
• Measured in Joules
• Examples of electrical energy:
  • Batteries
  • Lightning
  • Electrical charges moving through a wire

Nuclear Energy

• Nuclear energy is released from the nucleus of atoms
• In nuclear power plants, energy is released through fission reactions
• In stars, energy is released through fusion reactions
• Einstein's equation: E = mc^2 (mass-energy equivalence)

Heat and Temperature

• Heat is a form of energy that can be transferred from one body to another
• Causes thermal expansion of objects
• Heat energy required to raise the temperature of a substance depends on:
  • Mass of the substance
  • Nature of the substance
  • Temperature difference
• Heat capacity or thermal capacity is the quantity of heat energy that results in a unit change in the temperature of the body
• Specific heat capacity is the amount of heat required per unit mass of the substance to raise the temperature by one unit

Phase Changes

• Phase changes occur due to the amount of energy in a substance
• Examples of phase changes:
  • Water freezing into ice
  • Ice melting into water
  • Water boiling into water vapor
• Water boils at 212 degrees Fahrenheit, but can be manipulated by impurities and altitude

Energy in Living Organisms

• Energy is required for survival and reproduction
• Energy is transformed into more usable forms for living organisms
• Plants utilize photosynthesis for the production of sugar and oxygen
• Cells utilize sugar as a source of energy through cellular respiration

Vibrations and Waves

• Vibrations are repeated back-and-forth motions of a particle when displaced from its equilibrium position
• Characterized by repeated motion at regular intervals (periodic motion)
• Vibrations and oscillations are the sources of all waves
• Waves transfer energy from one place to another without transporting the matter or the medium itself
• Common parts and characteristics of waves:
  • Crest
  • Trough
  • Amplitude
  • Wavelength
  • Frequency

Energy Types

• Energy is neither created nor destroyed, only converted from one type to another
• Types of energy:
  • Gravitational potential energy (GPE)
  • Kinetic energy (KE)
  • Thermal energy
  • Radiant energy
  • Chemical energy
  • Electrical energy
  • Nuclear energy

Gravitational Potential Energy (GPE)

• GPE is based on an object's height
• Calculated using the equation: GPE = mgh (mass, acceleration due to gravity, and height)
• Higher objects have more GPE

Kinetic Energy (KE)

• KE is greater if an object moves faster
• Calculated using the equation: KE = 1/2 mv^2 (mass and velocity)

Thermal Energy

• Thermal energy is due to the movement of particles in an object
• Higher thermal energy when particles are moving quickly, lower thermal energy when particles are moving slowly
• Can be transferred through:
  • Convection
  • Conduction
  • Radiation

Radiant Energy

• Radiant energy can transfer through empty space (vacuum)
• Types of radiant energy:
  • Electromagnetic radiation
  • Gravitational radiation
• Both types of radiant energy do not require matter to propagate
• Electromagnetic radiation can take the form of oscillating waves or particles called photons
• Gravitational radiation takes the form of waves that propagate through the curvature of spacetime
• All radiant energy travels at the speed of light (~300,000,000 meters per second)

Chemical Energy

• Chemical energy is stored in the bonds of chemical compounds
• A form of potential energy
• Exothermic reactions release energy, endothermic reactions absorb energy
• Examples of chemical energy:
  • Photosynthesis
  • Petroleum
  • Batteries

Electrical Energy

• Electrical energy is caused by moving electric charges
• Energy is the ability to do work or apply force to move an object
• The faster the electric charges move, the more electrical energy they carry
• Measured in Joules
• Examples of electrical energy:
  • Batteries
  • Lightning
  • Electrical charges moving through a wire

Nuclear Energy

• Nuclear energy is released from the nucleus of atoms
• In nuclear power plants, energy is released through fission reactions
• In stars, energy is released through fusion reactions
• Einstein's equation: E = mc^2 (mass-energy equivalence)

Heat and Temperature

• Heat is a form of energy that can be transferred from one body to another
• Causes thermal expansion of objects
• Heat energy required to raise the temperature of a substance depends on:
  • Mass of the substance
  • Nature of the substance
  • Temperature difference
• Heat capacity or thermal capacity is the quantity of heat energy that results in a unit change in the temperature of the body
• Specific heat capacity is the amount of heat required per unit mass of the substance to raise the temperature by one unit

Phase Changes

• Phase changes occur due to the amount of energy in a substance
• Examples of phase changes:
  • Water freezing into ice
  • Ice melting into water
  • Water boiling into water vapor
• Water boils at 212 degrees Fahrenheit, but can be manipulated by impurities and altitude

Energy in Living Organisms

• Energy is required for survival and reproduction
• Energy is transformed into more usable forms for living organisms
• Plants utilize photosynthesis for the production of sugar and oxygen
• Cells utilize sugar as a source of energy through cellular respiration

Vibrations and Waves

• Vibrations are repeated back-and-forth motions of a particle when displaced from its equilibrium position
• Characterized by repeated motion at regular intervals (periodic motion)
• Vibrations and oscillations are the sources of all waves
• Waves transfer energy from one place to another without transporting the matter or the medium itself
• Common parts and characteristics of waves:
  • Crest
  • Trough
  • Amplitude
  • Wavelength
  • Frequency

Learn about the conservation of energy, which states that energy is neither created nor destroyed, but transformed from one type to another. This concept is applied to gravitational potential energy, calculated using the equation mgh.