Homework 8/21/15
8.21.1
Work is commonly give as Force times distance. If 100 lbf moves and object 356 inches. What is the work
in (a) Joules, (b) Btu
Ans: 4,020 Joules; 3.81 Btu
8.21.2
If 0.3 Btu of work done by an object by a 10N force, how far did the

Homework assigned 9/25
9.25.1 A piston-cylinder filled with air is compressed from 10 psi, 40oF to a final volume
of 1 ft3 in a polytrophic process where n = 1.4. The mass of the air is 1lbm. Determine the
work and heat transfer using a) constant specific

Homework assigned 9/23
9.23.1
O2 at 20oC and 200 bar is to be stored in a rigid container. The capacity of the container is
0.04 m3. What is the mass O2 that can be stored in the container? A fusible plug is used to
prevent the pressure from exceeding the

Homework assigned 9/21
9.21.1
Argon at 200 bar is to be stored in a steel vessel at 20oC. The capacity of the vessel is
0.04 m3. Determine the mass of argon that can be stored in the vessel. The vessel is
protected against excessive pressure by a fusible

Homework assigned 8/24
8.24.1) 400 lbm of propane is contained in a tank which is spherical and has a diameter of 18 ft. For the
air, determine a) the specific volume and b) weight where the gravity is 31 ft/sec 2.
Ans: 7.63 ft3/lbm, 385 lbf
8.24.2) A pis

Homework assigned 8/26
8.26.1 A system has an initial volume of 15 f 3 and expands to a final volume of 25 f 3. The initial
pressure is 24.7 psia. Find the work done if the pressure between the initial and final state is (a)
constant, (b) inversely propor

Homework 8/31/15
8.31.1
1 m3of air in a piston cylinder starts out as a pressure of 1 bar has and internal energy of 400 kJ. It ends
up at a volume of 0.1 m3, pressure of 10 bar and internal energy of 450 kJ
a) If the process is such that it goes from the

Homework assigned 9/2
9.2.1 A heat engine is known to operate at 58.3% efficiency that rejecting 500 Btu/lbm of heat. What is
the work out of the engine?
Ans: 700 Btu/lbm
9.2.2 A heat pump has a COP of 2.9. Determine the heat (a) transferred to and (b) fr

Assigned 9/4
9.4.1
Using Excel and the data in the charts in the back of the book plot temp (vertical axis) vs specific volume
(horizontal axis) for water at 10psi, 14.7 psia, and 100 psia, as the Temperature goes from 70 oF to
1,000oF. PUT ALL THREE CURV

Homework assigned 9/9
9.9.1 For each of the following determine if it is liquid, saturated vapor
Material
Temp. Press.
(F)
(PSI)
Water
Water
Water
Water
Water
Water
Water
Water
Water
350
350
350
350
Specific
Vol.
(ft3/lbm)
Int. Energy
(Btu/lbm)
X
Phase
(L

Homework assigned 9/16
9.16.1 H2O at P = 300 psia and T = 500oF is in a piston/cylinder device. Heat is transferred to the device
so that the volume is twice the initial volume while the pressure remains constant. (a) Sketch the process
on a P-v diagram,

Homework assigned 9/18
9.18.1
What is the compressibility factor for each of the following?
Argon
30 atm
70oF
Ethane
10 atm
0oF
Methane
10 atm
70oF
R12
1 atm
0oF
Nitrogen
10 atm
170oF
9.18.2
Can the following be considered an ideal gas?
CO2
1 atm
70oF
H2