| A | B |
|---|
| Conduction | the transfer of energy from the more energetic particles of a substance to the adjacent less energetic ones as a result of interaction between particles |
| convection | the transfer of energy between a solid surface and the adjacent fluid that is in motion, and it involves the combined effects of of conduction and fluid motion |
| radiation | the transfer of energy due to the emission of electromagnetic waves (photons) |
| work | If the energy crossing the boundary of a closed system is not heat, then it must be ___ |
| work | _____ is the energy transfer associated with a force acting through a distance |
| w=W/m | the work done per unit mass |
| power | the work done per unit time, unit of kJ/s or kW |
| directional quantities | heat and work are ____ and thus the complete description of a heat or work interaction requires the specification of both magnitude and direction |
| positive, negative | heat transfer to a system and work done b a system are _____. Heat transfer from a system and work done on a system are ____ |
| boundary | both heat and work are recognized as the boundaries of a system as they cross the boundaries. Thatis, both heat and work are ____ phenomena |
| systems | _____ posess energy, but not heat or work |
| process | heat and work are associated with a _____, not a state. Unlike properties, heat or work has no meaning as a state |
| path functions | both heat and work are ____ meaning that their magnitudes depend on the path followed during a process as well as the end states |
| Path functions, inexact differentials | ____ have ____, designated by the symbol delta instead of d |
| point functions, exact differentials | properties are ___, meaning that they depend on the state ony and not on how the system reaches that state, and they have ____ designated by the symbol d |
| equation for electrical work | w=VN |
| equation for electrical power | w=VI |
| basic equation for mechanical work | w=Fs |
| force, move | there are two requirements for a work interaction between a system and its surroundings to exist: 1) there must be a ____ acting on the boundary, and 2) the boundary must ____ |
| equation for shaft work | w=2*pi*n*t |
| work done by a spring | w=1/2*K*X^2 |
| work done on elastic solid bar | w=int(sigma.n*A*dx) |
| Work associated with stretchng a liquid film | w=int(sigma.s*dA) |
| potential energy, kinetic energy | work transfer needed to raise a body is equal to the change in the ____ of the body and work needed to accelarate a body is equal t the change in ______ of the body |
| electrical work, voltace, electrical charge | some examples of nonmechanical work modes are ____, where the generalized force is the ___ and the generalized displacement is the ____ |
| magnetic work, magnetic field strength, magnetic dipole moment | an example of a nonmechanical work mode called ____ has a gneralized force called the ____ and a generalized displacement called the magnetic ______ |
| electric field strength, polarization of the medium | electrical polarization work has a generalized force called the ____, and a generalized displacement called the ____ |
| adiabatic | for all _____ processes between two specified states of a closed system, the net work done is the same regardless of the nature of the closed system and the details of the process |
| net change | the ____ in the total energy of the system during a process ie equal to the difference between the total energy entering and the total energy leaving the system during that processs |
| stationary systems | for ___, the changes in kinetic and potential energy are zero |
| delta U | = m(u2-u1) |
| delta KE | = 1/2 m*(V2^2-V1^2) |
| delta PE | = mg*(Z2-Z1) |
| heat, work, mass flow | energy can be transferred to or froom a system in three forms: __, ___ and ___ |
| heat transfer | ______ to a system increases the energy of the molecules and thus the internal energy of the system |
| work transfer | ____ is an energy interaction that is not caused by a temperature difference between a system and its surroundings. _____ to a system increases the energy of the system. It is the work done on a system. _____ from a system is the work done by a system |
| mass flow | ____ to or from a system serves as a mechnaism for energy transfer because mass entering a system contains energy |
| heat transfer, work transfer, closed systems | the ____ is zero for adiabatic systems, the ____ is zero for systems that involve no work interactions, and the energy transport with mass Emass is zero for ____ |
| cycle | for a closed system undergoing a ___. tje omotoa; amd foma; states are identical and thus dEsystem = E2-E1 = 0 |
| efficiency | ____ indicates how well an energy conversion or transfered process is accomplished |
| equation for efficiency | = desired output/required output |
