Lecture 2

Question 1

conservation of the quality of
energy, not the quantity

Answer 1

Energy Conservation

Question 2

Highest quality of energy

Answer 2

Electricity

Question 3

Energy can exist in numerous forms such as thermal,
mechanical, potential, electric, magnetic, chemical, and
nuclear, and their sum constitutes ___________

Answer 3

total energy E

Question 4

total energy per unit mass

Answer 4

e

Question 5

Thermodynamics provides no information about the
absolute value of the total energy. It deals only with the ___________

Answer 5

change of the total energy

Question 6

are those a system
possesses as a whole with respect to some outside
reference frame, such as kinetic and potential energies

Answer 6

macroscopic forms of energy

Question 7

are those related to the
molecular structure of a system and the degree of the
molecular activity, and they are independent of outside
reference frame

Answer 7

microscopic forms of energy

Question 8

The sum of all the microscopic forms of
energy. Denoted by U

Answer 8

Internal energy

Question 9

is related to motion
and the influence of some external effects such as
gravity, magnetism, electricity, and surface tension

Answer 9

macroscopic energy of a system

Question 10

energy that a system possesses as a
result of its motion relative to some reference frame

Answer 10

kinetic energy (KE)

Question 11

the energy that a system
possesses as a result of its elevation in a gravitational
field

Answer 11

potential energy (PE)

Question 12

Closed systems whose velocity and elevation of the
center of gravity remain constant during a process are
often referred to as _________

Answer 12

stationary systems

Question 13

Pthe amount of mass flowing through
a cross section per unit time

Answer 13

mass flow rate ṁ

Question 14

which is the volume of a fluid
flowing through a cross section per unit time

Answer 14

volume flow rate V

Question 15

the form of
energy that can be converted to
mechanical work completely
and directly by an ideal
mechanical device such as an
ideal turbine

Answer 15

Mechanical Energy

Question 16

familiar forms of mechanical energy

Answer 16

Kinetic and Potential Energy

Question 17

A pressure force acting on a fluid through a distance
produces work

Answer 17

Flow work

Question 18

Energy can cross the boundary of a closed system in two
distinct forms:______&________

Answer 18

heat and work

Question 19

is energy in transition.
It is recognized only as it
crosses the boundary of a
system.

Answer 19

Heat

Question 20

A process during which
there is no heat transfer is
called an ____________.

Answer 20

adiabatic process

Question 21

two ways a process can be adiabatic:

Answer 21

• well insulated
• both the system and the surroundings are at the
  same temperature

Question 22

the amount of heat
transferred per unit
time

Answer 22

rate of heat transfer

Question 23

is an energy interaction between a system and its
surroundings

Answer 23

Work

Question 24

an energy interaction that is not caused by a
temperature difference between a system and
its surroundings

Answer 24

work

Question 25

The work done per unit time is _______

Answer 25

power and is denoted Ẇ.

Question 26

formal sign convention for heat and work interactions

Answer 26

- heat transfer to a system and work done by a system are positive; - heat transfer from a system and work done on a system are negative.

Question 27

have inexact differentials designated by the symbol δ

Answer 27

Path functions

Question 28

are point functions(i.e., they depend on the state only, and not on how a system reaches that state), and they have exact differentials designated by the symbol d

Answer 28

Properties

Question 29

increases the energy of the molecules and thus the internal energy of the system

Answer 29

Heat Transfer, Q

Question 30

An energy interaction that is not caused by a temperature difference between a system and its surroundings is work

Answer 30

Work Transfer, W

Question 31

serves as an additional mechanism of energy transfer. When mass enters a system, the energy of the system increases because mass carries energy with it

Answer 31

Mass Flow, m

Question 32

is defined as the ratio of the energy delivered to the house by hot water to the energy supplied to the water heater

Answer 32

efficiency of a water heater

Question 33

which is the ratio of the electrical power output to the mechanical power input.

Answer 33

Generator efficiency

Question 34

Is usually defined as the ratio of the net shaft work output of the turbine to the heat input to the working fluid

Answer 34

thermal efficiency of a power plant

Question 35

the ratio of the net electrical power output to the rate of fuel energy input

Answer 35

overall efficiency for the power plant

Question 36

defined as the amount of light output in lumens per W of electricity consumed

Answer 36

lighting efficacy

Question 37

can be defined as the ratio of the useful energy transferred to the food to the energy consumed by the appliance

Answer 37

efficiency of a cooking appliance

Question 38

The portion of the internal energy of a system associated with the kinetic energies of the molecules is called the ____________

Answer 38

sensible energy

Question 39

The internal energy associated with the phase of a system is called the ___________

Answer 39

latent energy

Question 40

The internal energy associated with the atomic bonds in a molecule is called ___________

Answer 40

chemical energy

Question 41

The tremendous amount of energy associated with the strong bonds within the nucleus of the atom itself is called ___________

Answer 41

nuclear energy