Heat, Energy, and Electromagnetic Radiation

• Heat is a form of energy and its release can do useful work.
• Thermal energy is the term for heat.
• Specific gravity is determined by comparing the density of liquids to water, using comparative densities or specific gravities.
• Gasoline with a specific gravity of 0.72 weighs 72% of the same amount of water.
• Atoms constitutes the smallest form of matter.

Electrons in Shells

• The maximum number of electrons in each shell of an atom equals 2n^2, where n represents the shell number.

Electromagnetic Radiation

• Electromagnetic radiation refers to the emission of energy from the surface of most objects and the acceleration of charged particles

Light Waves vs. Mechanical Waves

• Mechanical waves need a medium like air, water, or rope to travel through.
• Light waves, a type of electromagnetic wave, don't require a medium.
• Radiation is a type of heat transfer that doesn't require a medium.
• The second law of thermodynamics states that heat flows from a warmer body to a cooler body.
• Pascal's law describes pressure traveling in all directions in liquid kinetics.
• A force is anything that can produce a change in a body's state of motion.

Mechanical Advantage

• Mechanical advantage is calculated as load/effort or energy output/energy input.
• A crowbar exemplifies a first-class lever, with the fulcrum positioned between the load and the effort.
• A couple is two equal forces acting in parallel but opposite directions on two different points of a body.
• Stress refers to the force acting through a section of solid material, measured as force per unit area.
• Strain represents the deformation of a material resulting from stress.
• The pressure exerted by a column of liquid is determined by the vertical height of the column, gravity, and fluid density.
• Density is defined as mass per unit volume of a substance.
• Specific gravity is calculated as the density of a substance divided by the density of water.
• Water is the substance to which the weight of another substance is compared when calculating specific gravity.
• Speed describes the rate of change in distance with respect to time, while velocity describes the rate of change in displacement with respect to time.
• Force equals mass times acceleration (F = ma).
• Displacement refers to an object's position relative to its origin, distinct from distance, which is the total length traveled.
• Centripetal force pulls an object moving in a circular motion towards the center.
• The period in motion refers to the time it takes for one complete repetition or cycle, typically measured in seconds.
• A Brayton cycle engine refers to a gas turbine engine.
• Joule is the SI unit for all forms of energy and it provides the capacity for work to be done.
• Potential energy is stored energy. friction

Friction Types

• Static
• Sliding
• Rolling

Momentum Types

• Linear
• Angular
• Linear momentum measures the tendency of a moving body to continue in a straight line.
• Angular momentum measures the tendency of a rotating body to continue spinning.
• Efficiency ratio is the work output divided by the work input.
• If 100 joules of work input results in 90 joules of output, the efficiency is 90%.
• Impulse is the change in momentum of a body when a force is applied, altering its state of motion.

Gyroscope Principles

• Inertia (rigidity in space)
• Precession
• Gyroscopic rigidity is the property of a rotating mass resisting changes to its plane of rotation.
• Precession refers to the change in the plane of rotation caused by an external force.
• Viscosity is the stiffness of a fluid and its resistance to flow.
• The properties of oil with a low viscosity index do not change much over a wide range of operating temperatures.
• Static pressure decreases if velocity increases.
• Conduction is the transfer of heat through physical contact between bodies with different heat levels.
• Specific heat is the number of calories needed to raise the temperature of 1 gram of a substance by 1 degree Celsius.

Temperature Units

• Celsius
• Kelvin
• K = °C + 273
• °C = K - 273
• The general gas law formula combines Boyle's and Charles' laws as P1V1/T1 = P2V2/T2 using absolute temperature and pressure values.
• The angle of reflection equals the angle of incidence.
• Refraction occurs when a light wave hits water.
• Total internal reflection is the important phenomenon for optical fiber.
• Sound waves are compression waves using mechanical action of molecules to transfer action through a medium.
• The amplitude determines the intensity of sound.
• Two similar sound waves arriving at the ear simultaneously but out of phase will cancel each other out.